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News for the tz database
Release 2024b - 2024-09-04 12:27:47 -0700
Briefly:
Improve historical data for Mexico, Mongolia, and Portugal.
System V names are now obsolescent.
The main data form now uses %z.
The code now conforms to RFC 8536 for early timestamps.
Support POSIX.1-2024, which removes asctime_r and ctime_r.
Assume POSIX.2-1992 or later for shell scripts.
SUPPORT_C89 now defaults to 1.
Changes to past timestamps
Asia/Choibalsan is now an alias for Asia/Ulaanbaatar rather than
being a separate Zone with differing behavior before April 2008.
This seems better given our wildly conflicting information about
Mongolia's time zone history. (Thanks to Heitor David Pinto.)
Historical transitions for Mexico have been updated based on
official Mexican decrees. The affected timestamps occur during
the years 1921-1927, 1931, 1945, 1949-1970, and 1981-1997.
The affected zones are America/Bahia_Banderas, America/Cancun,
America/Chihuahua, America/Ciudad_Juarez, America/Hermosillo,
America/Mazatlan, America/Merida, America/Mexico_City,
America/Monterrey, America/Ojinaga, and America/Tijuana.
(Thanks to Heitor David Pinto.)
Historical transitions for Portugal, represented by Europe/Lisbon,
Atlantic/Azores, and Atlantic/Madeira, have been updated based on a
close reading of old Portuguese legislation, replacing previous data
mainly originating from Whitman and Shanks & Pottenger. These
changes affect a few transitions in 1917-1921, 1924, and 1940
throughout these regions by a few hours or days, and various
timestamps between 1977 and 1993 depending on the region. In
particular, the Azores and Madeira did not observe DST from 1977 to
1981. Additionally, the adoption of standard zonal time in former
Portuguese colonies have been adjusted: Africa/Maputo in 1909, and
Asia/Dili by 22 minutes at the start of 1912.
(Thanks to Tim Parenti.)
Changes to past tm_isdst flags
The period from 1966-04-03 through 1966-10-02 in Portugal is now
modeled as DST, to more closely reflect how contemporaneous changes
in law entered into force.
Changes to data
Names present only for compatibility with UNIX System V
(last released in the 1990s) have been moved to 'backward'.
These names, which for post-1970 timestamps mostly just duplicate
data of geographical names, were confusing downstream uses.
Names moved to 'backward' are now links to geographical names.
This affects behavior for TZ='EET' for some pre-1981 timestamps,
for TZ='CET' for some pre-1947 timestamps, and for TZ='WET' for
some pre-1996 timestamps. Also, TZ='MET' now behaves like
TZ='CET' and so uses the abbreviation "CET" rather than "MET".
Those needing the previous TZDB behavior, which does not match any
real-world clocks, can find the old entries in 'backzone'.
(Problem reported by Justin Grant.)
The main source files' time zone abbreviations now use %z,
supported by zic since release 2015f and used in vanguard form
since release 2022b. For example, America/Sao_Paulo now contains
the zone continuation line "-3:00 Brazil %z", which is less error
prone than the old "-3:00 Brazil -03/-02". This does not change
the represented data: the generated TZif files are unchanged.
Rearguard form still avoids %z, to support obsolescent parsers.
Asia/Almaty has been removed from zonenow.tab as it now agrees
with Asia/Tashkent for future timestamps, due to Kazakhstan's
2024-02-29 time zone change. Similarly, America/Scoresbysund
has been removed, as it now agrees with America/Nuuk due to
its 2024-03-31 time zone change.
Changes to code
localtime.c now always uses a TZif file's time type 0 to handle
timestamps before the file's first transition. Formerly,
localtime.c sometimes inferred a different time type, in order to
handle problematic data generated by zic 2018e or earlier. As it
is now safe to assume more recent versions of zic, there is no
longer a pressing need to fail to conform RFC 8536 section 3.2,
which requires using time type 0 in this situation. This change
does not affect behavior when reading TZif files generated by zic
2018f and later.
POSIX.1-2024 removes asctime_r and ctime_r and does not let
libraries define them, so remove them except when needed to
conform to earlier POSIX. These functions are dangerous as they
can overrun user buffers. If you still need them, add
-DSUPPORT_POSIX2008 to CFLAGS.
The SUPPORT_C89 option now defaults to 1 instead of 0, fixing a
POSIX-conformance bug introduced in 2023a.
tzselect now supports POSIX.1-2024 proleptic TZ strings. Also, it
assumes POSIX.2-1992 or later, as practical porting targets now
all support that, and it uses some features from POSIX.1-2024 if
available.
Changes to build procedure
'make check' no longer requires curl and Internet access.
The build procedure now assumes POSIX.2-1992 or later, to simplify
maintenance. To build on Solaris 10, the only extant system still
defaulting to pre-POSIX, prepend /usr/xpg4/bin to PATH.
Changes to documentation
The documentation now reflects POSIX.1-2024.
Changes to commentary
Commentary about historical transitions in Portugal and her former
colonies has been expanded with links to many relevant legislation.
(Thanks to Tim Parenti.)
Release 2024a - 2024-02-01 09:28:56 -0800
Briefly:
Kazakhstan unifies on UTC+5 beginning 2024-03-01.
Palestine springs forward a week later after Ramadan.
zic no longer pretends to support indefinite-past DST.
localtime no longer mishandles Ciudad Juárez in 2422.
Changes to future timestamps
Kazakhstan unifies on UTC+5. This affects Asia/Almaty and
Asia/Qostanay which together represent the eastern portion of the
country that will transition from UTC+6 on 2024-03-01 at 00:00 to
join the western portion. (Thanks to Zhanbolat Raimbekov.)
Palestine springs forward a week later than previously predicted
in 2024 and 2025. (Thanks to Heba Hamad.) Change spring-forward
predictions to the second Saturday after Ramadan, not the first;
this also affects other predictions starting in 2039.
Changes to past timestamps
Asia/Ho_Chi_Minh's 1955-07-01 transition occurred at 01:00
not 00:00. (Thanks to Đoàn Trần Công Danh.)
From 1947 through 1949, Toronto's transitions occurred at 02:00
not 00:00. (Thanks to Chris Walton.)
In 1911 Miquelon adopted standard time on June 15, not May 15.
Changes to code
The FROM and TO columns of Rule lines can no longer be "minimum"
or an abbreviation of "minimum", because TZif files do not support
DST rules that extend into the indefinite past - although these
rules were supported when TZif files had only 32-bit data, this
stopped working when 64-bit TZif files were introduced in 1995.
This should not be a problem for realistic data, since DST was
first used in the 20th century. As a transition aid, FROM columns
like "minimum" are now diagnosed and then treated as if they were
the year 1900; this should suffice for TZif files on old systems
with only 32-bit time_t, and it is more compatible with bugs in
2023c-and-earlier localtime.c. (Problem reported by Yoshito
Umaoka.)
localtime and related functions no longer mishandle some
timestamps that occur about 400 years after a switch to a time
zone with a DST schedule. In 2023d data this problem was visible
for some timestamps in November 2422, November 2822, etc. in
America/Ciudad_Juarez. (Problem reported by Gilmore Davidson.)
strftime %s now uses tm_gmtoff if available. (Problem and draft
patch reported by Dag-Erling Smørgrav.)
Changes to build procedure
The leap-seconds.list file is now copied from the IERS instead of
from its downstream counterpart at NIST, as the IERS version is
now in the public domain too and tends to be more up-to-date.
(Thanks to Martin Burnicki for liaisoning with the IERS.)
Changes to documentation
The strftime man page documents which struct tm members affect
which conversion specs, and that tzset is called. (Problems
reported by Robert Elz and Steve Summit.)
Release 2023d - 2023-12-21 20:02:24 -0800
Briefly:
Ittoqqortoormiit, Greenland changes time zones on 2024-03-31.
Vostok, Antarctica changed time zones on 2023-12-18.
Casey, Antarctica changed time zones five times since 2020.
Code and data fixes for Palestine timestamps starting in 2072.
A new data file zonenow.tab for timestamps starting now.
Changes to future timestamps
Ittoqqortoormiit, Greenland (America/Scoresbysund) joins most of
the rest of Greenland's timekeeping practice on 2024-03-31, by
changing its time zone from -01/+00 to -02/-01 at the same moment
as the spring-forward transition. Its clocks will therefore not
spring forward as previously scheduled. The time zone change
reverts to its common practice before 1981.
Fix predictions for DST transitions in Palestine in 2072-2075,
correcting a typo introduced in 2023a.
Changes to past and future timestamps
Vostok, Antarctica changed to +05 on 2023-12-18. It had been at
+07 (not +06) for years. (Thanks to Zakhary V. Akulov.)
Change data for Casey, Antarctica to agree with timeanddate.com,
by adding five time zone changes since 2020. Casey is now at +08
instead of +11.
Changes to past tm_isdst flags
Much of Greenland, represented by America/Nuuk, changed its
standard time from -03 to -02 on 2023-03-25, not on 2023-10-28.
This does not affect UTC offsets, only the tm_isdst flag.
(Thanks to Thomas M. Steenholdt.)
New data file
A new data file zonenow.tab helps configure applications that use
timestamps dated from now on. This simplifies configuration,
since users choose from a smaller Zone set. The file's format is
experimental and subject to change.
Changes to code
localtime.c no longer mishandles TZif files that contain a single
transition into a DST regime. Previously, it incorrectly assumed
DST was in effect before the transition too. (Thanks to Alois
Treindl for debugging help.)
localtime.c's timeoff no longer collides with OpenBSD 7.4.
The C code now uses _Generic only if __STDC_VERSION__ says the
compiler is C11 or later.
tzselect now optionally reads zonenow.tab, to simplify when
configuring only for timestamps dated from now on.
tzselect no longer creates temporary files.
tzselect no longer mishandles the following:
Spaces and most other special characters in BUGEMAIL, PACKAGE,
TZDIR, and VERSION.
TZ strings when using mawk 1.4.3, which mishandles regular
expressions of the form /X{2,}/.
ISO 6709 coordinates when using an awk that lacks the GNU
extension of newlines in -v option-arguments.
Non UTF-8 locales when using an iconv command that lacks the GNU
//TRANSLIT extension.
zic no longer mishandles data for Palestine after the year 2075.
Previously, it incorrectly omitted post-2075 transitions that are
predicted for just before and just after Ramadan. (Thanks to Ken
Murchison for debugging help.)
zic now works again on Linux 2.6.16 and 2.6.17 (2006).
(Problem reported by Rune Torgersen.)
Changes to build procedure
The Makefile is now more compatible with POSIX:
* It no longer defines AR, CC, CFLAGS, LDFLAGS, and SHELL.
* It no longer uses its own 'cc' in place of CC.
* It now uses ARFLAGS, with default specified by POSIX.
* It does not use LFLAGS incompatibly with POSIX.
* It uses the special .POSIX target.
* It quotes special characters more carefully.
* It no longer mishandles builds in an ISO 8859 locale.
Due to the CC changes, TZDIR is now #defined in a file tzdir.h
built by 'make', not in a $(CC) -D option. Also, TZDEFAULT is
now treated like TZDIR as they have similar roles.
Changes to commentary
Limitations and hazards of the optional support for obsolescent
C89 platforms are documented better, along with a tentative
schedule for removing this support.
Release 2023c - 2023-03-28 12:42:14 -0700
Changes to past and future timestamps
Model Lebanon's DST chaos by reverting data to tzdb 2023a.
(Thanks to Rany Hany for the heads-up.)
Release 2023b - 2023-03-23 19:50:38 -0700
Changes to future timestamps
This year Lebanon springs forward April 20/21 not March 25/26.
(Thanks to Saadallah Itani.) [This was reverted in 2023c.]
Release 2023a - 2023-03-22 12:39:33 -0700
Briefly:
Egypt now uses DST again, from April through October.
This year Morocco springs forward April 23, not April 30.
Palestine delays the start of DST this year.
Much of Greenland still uses DST from 2024 on.
America/Yellowknife now links to America/Edmonton.
tzselect can now use current time to help infer timezone.
The code now defaults to C99 or later.
Fix use of C23 attributes.
Changes to future timestamps
Starting in 2023, Egypt will observe DST from April's last Friday
through October's last Thursday. (Thanks to Ahmad ElDardiry.)
Assume the transition times are 00:00 and 24:00, respectively.
In 2023 Morocco's spring-forward transition after Ramadan
will occur April 23, not April 30. (Thanks to Milamber.)
Adjust predictions for future years accordingly. This affects
predictions for 2023, 2031, 2038, and later years.
This year Palestine will delay its spring forward from
March 25 to April 29 due to Ramadan. (Thanks to Heba Hamad.)
Make guesses for future Ramadans too.
Much of Greenland, represented by America/Nuuk, will continue to
observe DST using European Union rules. When combined with
Greenland's decision not to change the clocks in fall 2023,
America/Nuuk therefore changes from -03/-02 to -02/-01 effective
2023-10-29 at 01:00 UTC. (Thanks to Thomas M. Steenholdt.)
This change from 2022g doesn't affect timestamps until 2024-03-30,
and doesn't affect tm_isdst until 2023-03-25.
Changes to past timestamps
America/Yellowknife has changed from a Zone to a backward
compatibility Link, as it no longer differs from America/Edmonton
since 1970. (Thanks to Almaz Mingaleev.) This affects some
pre-1948 timestamps. The old data are now in 'backzone'.
Changes to past time zone abbreviations
When observing Moscow time, Europe/Kirov and Europe/Volgograd now
use the abbreviations MSK/MSD instead of numeric abbreviations,
for consistency with other timezones observing Moscow time.
Changes to code
You can now tell tzselect local time, to simplify later choices.
Select the 'time' option in its first prompt.
You can now compile with -DTZNAME_MAXIMUM=N to limit time zone
abbreviations to N bytes (default 255). The reference runtime
library now rejects POSIX-style TZ strings that contain longer
abbreviations, treating them as UTC. Previously the limit was
platform dependent and abbreviations were silently truncated to
16 bytes even when the limit was greater than 16.
The code by default is now designed for C99 or later. To build on
a mostly-C89 platform, compile with -DPORT_TO_C89; this should
work on C89 platforms that also support C99 'long long' and
perhaps a few other extensions to C89. To support C89 callers of
tzcode's library, compile with -DSUPPORT_C89; however, this could
trigger latent bugs in C99-or-later callers. The two new macros
are transitional aids planned to be removed in a future version
(say, in 2029), when C99 or later will be required.
The code now builds again on pre-C99 platforms, if you compile
with -DPORT_TO_C89. This fixes a bug introduced in 2022f.
On C23-compatible platforms tzcode no longer uses syntax like
'static [[noreturn]] void usage(void);'. Instead, it uses
'[[noreturn]] static void usage(void);' as strict C23 requires.
(Problem reported by Houge Langley.)
The code's functions now constrain their arguments with the C
'restrict' keyword consistently with their documentation.
This may allow future optimizations.
zdump again builds standalone with ckdadd and without setenv,
fixing a bug introduced in 2022g. (Problem reported by panic.)
leapseconds.awk can now process a leap seconds file that never
expires; this might be useful if leap seconds are discontinued.
Changes to commentary
tz-link.html has a new section "Coordinating with governments and
distributors". (Thanks to Neil Fuller for some of the text.)
To improve tzselect diagnostics, zone1970.tab's comments column is
now limited to countries that have multiple timezones.
Note that there are plans to discontinue leap seconds by 2035.
Release 2022g - 2022-11-29 08:58:31 -0800
Briefly:
The northern edge of Chihuahua changes to US timekeeping.
Much of Greenland stops changing clocks after March 2023.
Fix some pre-1996 timestamps in northern Canada.
C89 is now deprecated; please use C99 or later.
Portability fixes for AIX, libintl, MS-Windows, musl, z/OS
In C code, use more C23 features if available.
C23 timegm now supported by default
Fixes for unlikely integer overflows
Changes to future timestamps
In the Mexican state of Chihuahua, the border strip near the US
will change to agree with nearby US locations on 2022-11-30.
The strip's western part, represented by Ciudad Juárez, switches
from -06 all year to -07/-06 with US DST rules, like El Paso, TX.
The eastern part, represented by Ojinaga, will observe US DST next
year, like Presidio, TX. (Thanks to Heitor David Pinto.)
A new Zone America/Ciudad_Juarez splits from America/Ojinaga.
Much of Greenland, represented by America/Nuuk, stops observing
winter time after March 2023, so its daylight saving time becomes
standard time. (Thanks to Jonas Nyrup and Jürgen Appel.)
Changes to past timestamps
Changes for pre-1996 northern Canada (thanks to Chris Walton):
Merge America/Iqaluit and America/Pangnirtung into the former,
with a backward compatibility link for the latter name.
There is no good evidence the two locations differ since 1970.
This change affects pre-1996 America/Pangnirtung timestamps.
Cambridge Bay, Inuvik, Iqaluit, Rankin Inlet, Resolute and
Yellowknife did not observe DST in 1965, and did observe DST
from 1972 through 1979.
Whitehorse moved from -09 to -08 on 1966-02-27, not 1967-05-28.
Colombia's 1993 fallback was 02-06 24:00, not 04-04 00:00.
(Thanks to Alois Treindl.)
Singapore's 1981-12-31 change was at 16:00 UTC (23:30 local time),
not 24:00 local time. (Thanks to Geoff Clare via Robert Elz.)
Changes to code
Although tzcode still works with C89, bugs found in recent routine
maintenance indicate that bitrot has set in and that in practice
C89 is no longer used to build tzcode. As it is a maintenance
burden, support for C89 is planned to be removed soon. Instead,
please use compilers compatible with C99, C11, C17, or C23.
timegm, which tzcode implemented in 1989, will finally be
standardized 34 years later as part of C23, so timegm is now
supported even if STD_INSPIRED is not defined.
Fix bug in zdump's tzalloc emulation on hosts that lack tm_zone.
(Problem reported by Đoàn Trần Công Danh.)
Fix bug in zic on hosts where malloc(0) yields NULL on success.
(Problem reported by Tim McBrayer for AIX 6.1.)
Fix zic configuration to avoid linkage failures on some platforms.
(Problems reported by Gilmore Davidson and Igor Ivanov.)
Work around MS-Windows nmake incompatibility with POSIX.
(Problem reported by Manuela Friedrich.)
Port mktime and strftime to debugging platforms where accessing
uninitialized data has undefined behavior (strftime problem
reported by Robert Elz).
Check more carefully for unlikely integer overflows, preferring
C23 <stdckdint.h> to overflow checking by hand, as the latter has
had obscure bugs.
Changes to build procedure
New Makefile rule check_mild that skips checking whether Link
lines are in the file 'backward'. (Inspired by a suggestion from
Stephen Colebourne.)
Release 2022f - 2022-10-28 18:04:57 -0700
Briefly:
Mexico will no longer observe DST except near the US border.
Chihuahua moves to year-round -06 on 2022-10-30.
Fiji no longer observes DST.
Move links to 'backward'.
In vanguard form, GMT is now a Zone and Etc/GMT a link.
zic now supports links to links, and vanguard form uses this.
Simplify four Ontario zones.
Fix a Y2438 bug when reading TZif data.
Enable 64-bit time_t on 32-bit glibc platforms.
Omit large-file support when no longer needed.
In C code, use some C23 features if available.
Remove no-longer-needed workaround for Qt bug 53071.
Changes to future timestamps
Mexico will no longer observe DST after 2022, except for areas
near the US border that continue to observe US DST rules.
On 2022-10-30 at 02:00 the Mexican state of Chihuahua moves
from -07 (-06 with DST) to year-round -06, thus not changing
its clocks that day. The new law states that Chihuahua
near the US border no longer observes US DST.
(Thanks to gera for the heads-up about Chihuahua.)
Fiji will not observe DST in 2022/3. (Thanks to Shalvin Narayan.)
For now, assume DST is suspended indefinitely.
Changes to data
Move links to 'backward' to ease and simplify link maintenance.
This affects generated data only if you use 'make BACKWARD='.
GMT is now a Zone and Etc/GMT a link instead of vice versa,
as GMT is needed for leap second support whereas Etc/GMT is not.
However, this change exposes a bug in TZUpdater 2.3.2 so it is
present only in vanguard form for now.
Vanguard form now uses links to links, as zic now supports this.
Changes to past timestamps
Simplify four Ontario zones, as most of the post-1970 differences
seem to have been imaginary. (Problem reported by Chris Walton.)
Move America/Nipigon, America/Rainy_River, and America/Thunder_Bay
to 'backzone'; backward-compatibility links still work, albeit
with some different timestamps before November 2005.
Changes to code
zic now supports links to links regardless of input line order.
For example, if Australia/Sydney is a Zone, the lines
Link Australia/Canberra Australia/ACT
Link Australia/Sydney Australia/Canberra
now work correctly, even though the shell commands
ln Australia/Canberra Australia/ACT
ln Australia/Sydney Australia/Canberra
would fail because the first command attempts to use a link
Australia/Canberra that does not exist until after the second
command is executed. Previously, zic had unspecified behavior if
a Link line's target was another link, and zic often misbehaved if
a Link line's target was a later Link line.
Fix line number in zic's diagnostic for a link to a link.
Fix a bug that caused localtime to mishandle timestamps starting
in the year 2438 when reading data generated by 'zic -b fat' when
distant-future DST transitions occur at times given in standard
time or in UT, not the usual case of local time. This occurs when
the corresponding .zi Rule lines specify DST transitions with TO
columns of 'max' and AT columns that end in 's' or 'u'. The
number 2438 comes from the 32-bit limit in the year 2038, plus the
400-year Gregorian cycle. (Problem reported by Bradley White.)
On glibc 2.34 and later, which optionally supports 64-bit time_t
on platforms like x86 where time_t was traditionally 32 bits,
default time_t to 64 instead of 32 bits. This lets functions like
localtime support timestamps after the year 2038, and fixes
year-2038 problems in zic when accessing files dated after 2038.
To continue to limit time_t to 32 bits on these platforms, use
"make CFLAGS='-D_TIME_BITS=32'".
In C code, do not enable large-file support on platforms like AIX
and macOS that no longer need it now that tzcode does not use
off_t or related functions like 'stat'. Large-file support is
still enabled by default on GNU/Linux, as it is needed for 64-bit
time_t support.
In C code, prefer C23 keywords to pre-C23 macros for alignof,
bool, false, and true. Also, use the following C23 features if
available: __has_include, unreachable.
zic no longer works around Qt bug 53071, as the relevant Qt
releases have been out of support since 2019. This change affects
only fat TZif files, as thin files never had the workaround.
zdump no longer modifies the environ vector when compiled on
platforms lacking tm_zone or when compiled with -DUSE_LTZ=0.
This avoid undefined behavior on POSIX platforms.
Release 2022e - 2022-10-11 11:13:02 -0700
Briefly:
Jordan and Syria switch from +02/+03 with DST to year-round +03.
Changes to future timestamps
Jordan and Syria are abandoning the DST regime and are changing to
permanent +03, so they will not fall back from +03 to +02 on
2022-10-28. (Thanks to Steffen Thorsen and Issam Al-Zuwairi.)
Changes to past timestamps
On 1922-01-01 Tijuana adopted standard time at 00:00, not 01:00.
Changes to past time zone abbreviations and DST flags
The temporary advancement of clocks in central Mexico in summer
1931 is now treated as daylight saving time, instead of as two
changes to standard time.
Release 2022d - 2022-09-23 12:02:57 -0700
Briefly:
Palestine transitions are now Saturdays at 02:00.
Simplify three Ukraine zones into one.
Changes to future timestamps
Palestine now springs forward and falls back at 02:00 on the
first Saturday on or after March 24 and October 24, respectively.
This means 2022 falls back 10-29 at 02:00, not 10-28 at 01:00.
(Thanks to Heba Hamad.)
Changes to past timestamps
Simplify three Ukraine zones to one, since the post-1970
differences seem to have been imaginary. Move Europe/Uzhgorod and
Europe/Zaporozhye to 'backzone'; backward-compatibility links
still work, albeit with different timestamps before October 1991.
Release 2022c - 2022-08-15 17:47:18 -0700
Briefly:
Work around awk bug in FreeBSD, macOS, etc.
Improve tzselect on intercontinental Zones.
Changes to code
Work around a bug in onetrueawk that broke commands like
'make traditional_tarballs' on FreeBSD, macOS, etc.
(Problem reported by Deborah Goldsmith.)
Add code to tzselect that uses experimental structured comments in
zone1970.tab to clarify whether Zones like Africa/Abidjan and
Europe/Istanbul cross continent or ocean boundaries.
(Inspired by a problem reported by Peter Krefting.)
Fix bug with 'zic -d /a/b/c' when /a is unwritable but the
directory /a/b already exists.
Remove zoneinfo2tdf.pl, as it was unused and triggered false
malware alarms on some email servers.
Release 2022b - 2022-08-10 15:38:32 -0700
Briefly:
Chile's DST is delayed by a week in September 2022.
Iran no longer observes DST after 2022.
Rename Europe/Kiev to Europe/Kyiv.
New zic -R option
Vanguard form now uses %z.
Finish moving duplicate-since-1970 zones to 'backzone'.
New build option PACKRATLIST
New tailored_tarballs target, replacing rearguard_tarballs
Changes to future timestamps
Chile's 2022 DST start is delayed from September 4 to September 11.
(Thanks to Juan Correa.)
Iran plans to stop observing DST permanently, after it falls back
on 2022-09-21. (Thanks to Ali Mirjamali.)
Changes to past timestamps
Finish moving to 'backzone' the location-based zones whose
timestamps since 1970 are duplicates; adjust links accordingly.
This change ordinarily affects only pre-1970 timestamps, and with
the new PACKRATLIST option it does not affect any timestamps.
In this round the affected zones are Antarctica/Vostok,
Asia/Brunei, Asia/Kuala_Lumpur, Atlantic/Reykjavik,
Europe/Amsterdam, Europe/Copenhagen, Europe/Luxembourg,
Europe/Monaco, Europe/Oslo, Europe/Stockholm, Indian/Christmas,
Indian/Cocos, Indian/Kerguelen, Indian/Mahe, Indian/Reunion,
Pacific/Chuuk, Pacific/Funafuti, Pacific/Majuro, Pacific/Pohnpei,
Pacific/Wake and Pacific/Wallis, and the affected links are
Arctic/Longyearbyen, Atlantic/Jan_Mayen, Iceland, Pacific/Ponape,
Pacific/Truk, and Pacific/Yap.
From fall 1994 through fall 1995, Shanks wrote that Crimea's
DST transitions were at 02:00 standard time, not at 00:00.
(Thanks to Michael Deckers.)
Iran adopted standard time in 1935, not 1946. In 1977 it observed
DST from 03-21 23:00 to 10-20 24:00; its 1978 transitions were on
03-24 and 08-05, not 03-20 and 10-20; and its spring 1979
transition was on 05-27, not 03-21.
(Thanks to Roozbeh Pournader and Francis Santoni.)
Chile's observance of -04 from 1946-08-29 through 1947-03-31 was
considered DST, not standard time. Santiago and environs had moved
their clocks back to rejoin the rest of mainland Chile; put this
change at the end of 1946-08-28. (Thanks to Michael Deckers.)
Some old, small clock transitions have been removed, as people at
the time did not change their clocks. This affects Asia/Hong_Kong
in 1904, Asia/Ho_Chi_Minh in 1906, and Europe/Dublin in 1880.
Changes to zone name
Rename Europe/Kiev to Europe/Kyiv, as "Kyiv" is more common in
English now. Spelling of other names in Ukraine has not yet
demonstrably changed in common English practice so for now these
names retain old spellings, as in other countries (e.g.,
Europe/Prague not "Praha", and Europe/Sofia not "Sofiya").
Changes to code
zic has a new option '-R @N' to output explicit transitions < N.
(Need suggested by Almaz Mingaleev.)
'zic -r @N' no longer outputs bad data when N < first transition.
(Problem introduced in 2021d and reported by Peter Krefting.)
zic now checks its input for NUL bytes and unterminated lines, and
now supports input line lengths up to 2048 (not 512) bytes.
gmtime and related code now use the abbreviation "UTC" not "GMT".
POSIX is being revised to require this.
When tzset and related functions set vestigial static variables
like tzname, they now prefer specified timestamps to unspecified ones.
(Problem reported by Almaz Mingaleev.)
zic no longer complains "can't determine time zone abbreviation to
use just after until time" when a transition to a new standard
time occurs simultaneously with the first DST fallback transition.
Changes to build procedure
Source data in vanguard form now uses the %z notation, introduced
in release 2015f. For example, for America/Sao_Paulo vanguard
form contains the zone continuation line "-3:00 Brazil %z", which
is simpler and more reliable than the line "-3:00 Brazil -03/-02"
used in main and rearguard forms. The plan is for the main form
to use %z eventually; in the meantime maintainers of zi parsers
are encouraged to test the parsers on vanguard.zi.
The Makefile has a new PACKRATLIST option to select a subset of
'backzone'. For example, 'make PACKRATDATA=backzone
PACKRATLIST=zone.tab' now generates TZif files identical to those
of the global-tz project.
The Makefile has a new tailored_tarballs target for generating
special-purpose tarballs. It generalizes and replaces the
rearguard_tarballs target and related targets and macros, which
are now obsolescent.
'make install' now defaults LOCALTIME to Factory not GMT,
which means the default abbreviation is now "-00" not "GMT".
Remove the posix_packrat target, marked obsolescent in 2016a.
Release 2022a - 2022-03-15 23:02:01 -0700
Briefly:
Palestine will spring forward on 2022-03-27, not -03-26.
zdump -v now outputs better failure indications.
Bug fixes for code that reads corrupted TZif data.
Changes to future timestamps
Palestine will spring forward on 2022-03-27, not 2022-03-26.
(Thanks to Heba Hamad.) Predict future transitions for first
Sunday >= March 25. Additionally, predict fallbacks to be the first
Friday on or after October 23, not October's last Friday, to be more
consistent with recent practice. The first differing fallback
prediction is on 2025-10-24, not 2025-10-31.
Changes to past timestamps
From 1992 through spring 1996, Ukraine's DST transitions were at
02:00 standard time, not at 01:00 UTC. (Thanks to Alois Treindl.)
Chile's Santiago Mean Time and its LMT precursor have been adjusted
eastward by 1 second to align with past and present law.
Changes to commentary
Add several references for Chile's 1946/1947 transitions, some of
which only affected portions of the country.
Changes to code
Fix bug when mktime gets confused by truncated TZif files with
unspecified local time. (Problem reported by Almaz Mingaleev.)
Fix bug when 32-bit time_t code reads malformed 64-bit TZif data.
(Problem reported by Christos Zoulas.)
When reading a version 2 or later TZif file, the TZif reader now
validates the version 1 header and data block only enough to skip
over them, as recommended by RFC 8536 section 4. Also, the TZif
reader no longer mistakenly attempts to parse a version 1 TZIf
file header as a TZ string.
zdump -v now outputs "(localtime failed)" and "(gmtime failed)"
when local time and UT cannot be determined for a timestamp.
Changes to build procedure
Distribution tarballs now use standard POSIX.1-1988 ustar format
instead of GNU format. Although the formats are almost identical
for these tarballs, ustar headers' magic fields contain "ustar"
instead of "ustar ", and their version fields contain "00" instead
of " ". The two formats are planned to diverge more significantly
for tzdb releases after 2242-03-16 12:56:31 UTC, when the ustar
format becomes obsolete and the tarballs switch to pax format, an
extension of ustar. For details about these formats, please see
"pax - portable archive interchange", IEEE Std 1003.1-2017,
<https://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13>.
Release 2021e - 2021-10-21 18:41:00 -0700
Changes to future timestamps
Palestine will fall back 10-29 (not 10-30) at 01:00.
(Thanks to P Chan and Heba Hemad.)
Release 2021d - 2021-10-15 13:48:18 -0700
Briefly:
Fiji suspends DST for the 2021/2022 season.
'zic -r' marks unspecified timestamps with "-00".
Changes to future timestamps
Fiji will suspend observance of DST for the 2021/2022 season.
Assume for now that it will return next year. (Thanks to Jashneel
Kumar and P Chan.)
Changes to code
'zic -r' now uses "-00" time zone abbreviations for intervals
with UT offsets that are unspecified due to -r truncation.
This implements a change in draft Internet RFC 8536bis.
Release 2021c - 2021-10-01 14:21:49 -0700
Briefly:
Revert most 2021b changes to 'backward'.
Fix 'zic -b fat' bug in pre-1970 32-bit data.
Fix two Link line typos.
Distribute SECURITY file.
This release is intended as a bugfix release, to fix compatibility
problems and typos reported since 2021b was released.
Changes to Link directives
Revert almost all of 2021b's changes to the 'backward' file,
by moving Link directives back to where they were in 2021a.
Although 'zic' doesn't care which source file contains a Link
directive, some downstream uses ran into trouble with the move.
(Problem reported by Stephen Colebourne for Joda-Time.)
Fix typo that linked Atlantic/Jan_Mayen to the wrong location
(problem reported by Chris Walton).
Fix 'backzone' typo that linked America/Virgin to the wrong
location (problem reported by Michael Deckers).
Changes to code
Fix a bug in 'zic -b fat' that caused old timestamps to be
mishandled in 32-bit-only readers (problem reported by Daniel
Fischer).
Changes to documentation
Distribute the SECURITY file (problem reported by Andreas Radke).
Release 2021b - 2021-09-24 16:23:00 -0700
Briefly:
Jordan now starts DST on February's last Thursday.
Samoa no longer observes DST.
Merge more location-based Zones whose timestamps agree since 1970.
Move some backward-compatibility links to 'backward'.
Rename Pacific/Enderbury to Pacific/Kanton.
Correct many pre-1993 transitions in Malawi, Portugal, etc.
zic now creates each output file or link atomically.
zic -L no longer omits the POSIX TZ string in its output.
zic fixes for truncation and leap second table expiration.
zic now follows POSIX for TZ strings using all-year DST.
Fix some localtime crashes and bugs in obscure cases.
zdump -v now outputs more-useful boundary cases.
tzfile.5 better matches a draft successor to RFC 8536.
A new file SECURITY.
This release is prompted by recent announcements by Jordan and Samoa.
It incorporates many other changes that had accumulated since 2021a.
However, it omits most proposed changes that merged all Zones
agreeing since 1970, as concerns were raised about doing too many of
these changes at once. It does keeps some of these changes in the
interest of making tzdb more equitable one step at a time; see
"Merge more location-based Zones" below.
Changes to future timestamps
Jordan now starts DST on February's last Thursday.
(Thanks to Steffen Thorsen.)
Samoa no longer observes DST. (Thanks to Geoffrey D. Bennett.)
Changes to zone name
Rename Pacific/Enderbury to Pacific/Kanton. When we added
Enderbury in 1993, we did not know that it is uninhabited and that
Kanton (population two dozen) is the only inhabited location in
that timezone. The old name is now a backward-compatibility link.
Changes to past timestamps
Correct many pre-1993 transitions, fixing entries originally
derived from Shanks, Whitman, and Mundell. The fixes include:
- Barbados: standard time was introduced in 1911, not 1932; and
DST was observed in 1942-1944
- Cook Islands: In 1899 they switched from east to west of GMT,
celebrating Christmas for two days. They (and Niue) switched
to standard time in 1952, not 1901.
- Guyana: corrected LMT for Georgetown; the introduction of
standard time in 1911, not 1915; and corrections to 1975 and
1992 transitions
- Kanton: uninhabited before 1937-08-31
- Niue: only observed -11:20 from 1952 through 1964, then went to
-11 instead of -11:30
- Portugal: DST was observed in 1950
- Tonga: corrected LMT; the introduction of standard time in 1945,
not 1901; and corrections to the transition from +12:20 to +13
in 1961, not 1941
Additional fixes to entries in the 'backzone' file include:
- Enderbury: inhabited only 1860/1885 and 1938-03-06/1942-02-09
- The Gambia: 1933 and 1942 transitions
- Malawi: several 1911 through 1925 transitions
- Sierra Leone: several 1913 through 1941 transitions, and DST
was NOT observed in 1957 through 1962
(Thanks to P Chan, Michael Deckers, Alexander Krivenyshev and
Alois Treindl.)
Merge more location-based Zones whose timestamps agree since 1970,
as pre-1970 timestamps are out of scope. This is part of a
process that has been ongoing since 2013. This does not affect
post-1970 timestamps, and timezone historians who build with 'make
PACKRATDATA=backzone' should see no changes to pre-1970 timestamps.
When merging, keep the most-populous location's data, and move
data for other locations to 'backzone' with a backward
link in 'backward'. For example, move America/Creston data to
'backzone' with a link in 'backward' from America/Phoenix because
the two timezones' timestamps agree since 1970; this change
affects some pre-1968 timestamps in America/Creston because
Creston and Phoenix disagreed before 1968. The affected Zones
are Africa/Accra, America/Atikokan, America/Blanc-Sablon,
America/Creston, America/Curacao, America/Nassau,
America/Port_of_Spain, Antarctica/DumontDUrville, and
Antarctica/Syowa.
Changes to maintenance procedure
The new file SECURITY covers how to report security-related bugs.
Several backward-compatibility links have been moved to the
'backward' file. These links, which range from Africa/Addis_Ababa
to Pacific/Saipan, are only for compatibility with now-obsolete
guidelines suggesting an entry for every ISO 3166 code.
The intercontinental convenience links Asia/Istanbul and
Europe/Nicosia have also been moved to 'backward'.
Changes to code
zic now creates each output file or link atomically,
possibly by creating a temporary file and then renaming it.
This avoids races where a TZ setting would temporarily stop
working while zic was installing a replacement file or link.
zic -L no longer omits the POSIX TZ string in its output.
Starting with 2020a, zic -L truncated its output according to the
"Expires" directive or "#expires" comment in the leapseconds file.
The resulting TZif files omitted daylight saving transitions after
the leap second table expired, which led to far less accurate
predictions of times after the expiry. Although future timestamps
cannot be converted accurately in the presence of leap seconds, it
is more accurate to convert near-future timestamps with a few
seconds error than with an hour error, so zic -L no longer
truncates output in this way.
Instead, when zic -L is given the "Expires" directive, it now
outputs the expiration by appending a no-change entry to the leap
second table. Although this should work well with most TZif
readers, it does not conform to Internet RFC 8536 and some pickier
clients (including tzdb 2017c through 2021a) reject it, so
"Expires" directives are currently disabled by default. To enable
them, set the EXPIRES_LINE Makefile variable. If a TZif file uses
this new feature it is marked with a new TZif version number 4,
a format intended to be documented in a successor to RFC 8536.
The old-format "#expires" comments are now treated solely as
comments and have no effect on the TZif files.
zic -L LEAPFILE -r @LO no longer generates an invalid TZif file
that omits leap second information for the range LO..B when LO
falls between two leap seconds A and B. Instead, it generates a
TZif version 4 file that represents the previously missing
information.
The TZif reader now allows the leap second table to begin with a
correction other than -1 or +1, and to contain adjacent
transitions with equal corrections. This supports TZif version 4.
The TZif reader now lets leap seconds occur less than 28 days
apart. This supports possible future TZif extensions.
Fix bug that caused 'localtime' etc. to crash when TZ was
set to a all-year DST string like "EST5EDT4,0/0,J365/25" that does
not conform to POSIX but does conform to Internet RFC 8536.
Fix another bug that caused 'localtime' etc. to crash when TZ was
set to a POSIX-conforming but unusual TZ string like
"EST5EDT4,0/0,J365/0", where almost all the year is DST.
Fix yet another bug that caused 'localtime' etc. to mishandle slim
TZif files containing leap seconds after the last explicit
transition in the table, or when handling far-future timestamps
in slim TZif files lacking leap seconds.
Fix localtime misbehavior involving positive leap seconds.
This change affects only behavior for "right" system time,
which contains leap seconds, and only if the UT offset is
not a multiple of 60 seconds when a positive leap second occurs.
(No such timezone exists in tzdb, luckily.) Without the fix,
the timestamp was ambiguous during a positive leap second.
With the fix, any seconds occurring after a positive leap second
and within the same localtime minute are counted through 60, not
through 59; their UT offset (tm_gmtoff) is the same as before.
Here is how the fix affects timestamps in a timezone with UT
offset +01:23:45 (5025 seconds) and with a positive leap second at
1972-06-30 23:59:60 UTC (78796800):
time_t without the fix with the fix
78796800 1972-07-01 01:23:45 1972-07-01 01:23:45 (leap second)
78796801 1972-07-01 01:23:45 1972-07-01 01:23:46
...
78796815 1972-07-01 01:23:59 1972-07-01 01:23:60
78796816 1972-07-01 01:24:00 1972-07-01 01:24:00
Fix an unlikely bug that caused 'localtime' etc. to misbehave if
civil time changes a few seconds before time_t wraps around, when
leap seconds are enabled.
Fix bug in zic -r; in some cases, the dummy time type after the
last time transition disagreed with the TZ string, contrary to
Internet RFC 8563 section 3.3.
Fix a bug with 'zic -r @X' when X is a negative leap second that
has a nonnegative correction. Without the fix, the output file
was truncated so that X appeared to be a positive leap second.
Fix a similar, even less likely bug when truncating at a positive
leap second that has a nonpositive correction.
zic -r now reports an error if given rolling leap seconds, as this
usage has never generally worked and is evidently unused.
zic now generates a POSIX-conforming TZ string for TZif files
where all-year DST is predicted for the indefinite future.
For example, for all-year Eastern Daylight Time, zic now generates
"XXX3EDT4,0/0,J365/23" where it previously generated
"EST5EDT,0/0,J365/25" or "". (Thanks to Michael Deckers for
noting the possibility of POSIX conformance.)
zic.c no longer requires sys/wait.h (thanks to spazmodius for
noting it wasn't needed).
When reading slim TZif files, zdump no longer mishandles leap
seconds on the rare platforms where time_t counts leap seconds,
fixing a bug introduced in 2014g.
zdump -v now outputs timestamps at boundaries of what localtime
and gmtime can represent, instead of the less useful timestamps
one day after the minimum and one day before the maximum.
(Thanks to Arthur David Olson for prototype code, and to Manuela
Friedrich for debugging help.)
zdump's -c and -t options are now consistently inclusive for the
lower time bound and exclusive for the upper. Formerly they were
inconsistent. (Confusion noted by Martin Burnicki.)
Changes to build procedure
You can now compile with -DHAVE_MALLOC_ERRNO=0 to port to
non-POSIX hosts where malloc doesn't set errno.
(Problem reported by Jan Engelhardt.)
Changes to documentation
tzfile.5 better matches a draft successor to RFC 8536
<https://datatracker.ietf.org/doc/draft-murchison-rfc8536bis/01/>.
Release 2021a - 2021-01-24 10:54:57 -0800
Changes to future timestamps
South Sudan changes from +03 to +02 on 2021-02-01 at 00:00.
(Thanks to Steffen Thorsen.)
Release 2020f - 2020-12-29 00:17:46 -0800
Change to build procedure
'make rearguard_tarballs' no longer generates a bad rearguard.zi,
fixing a 2020e bug. (Problem reported by Deborah Goldsmith.)
Release 2020e - 2020-12-22 15:14:34 -0800
Briefly:
Volgograd switches to Moscow time on 2020-12-27 at 02:00.
Changes to future timestamps
Volgograd changes time zone from +04 to +03 on 2020-12-27 at 02:00.
(Thanks to Alexander Krivenyshev and Stepan Golosunov.)
Changes to past timestamps
Correct many pre-1986 transitions, fixing entries originally
derived from Shanks. The fixes include:
- Australia: several 1917 through 1971 transitions
- The Bahamas: several 1941 through 1945 transitions
- Bermuda: several 1917 through 1956 transitions
- Belize: several 1942 through 1968 transitions
- Ghana: several 1915 through 1956 transitions
- Israel and Palestine: several 1940 through 1985 transitions
- Kenya and adjacent: several 1908 through 1960 transitions
- Nigeria and adjacent: correcting LMT in Lagos, and several 1905
through 1919 transitions
- Seychelles: the introduction of standard time in 1907, not 1906
- Vanuatu: DST in 1973-1974, and a corrected 1984 transition
(Thanks to P Chan.)
Because of the Australia change, Australia/Currie (King Island) is
no longer needed, as it is identical to Australia/Hobart for all
timestamps since 1970 and was therefore created by mistake.
Australia/Currie has been moved to the 'backward' file and its
corrected data moved to the 'backzone' file.
Changes to past time zone abbreviations and DST flags
To better match legislation in Turks and Caicos, the 2015 shift to
year-round observance of -04 is now modeled as AST throughout before
returning to Eastern Time with US DST in 2018, rather than as
maintaining EDT until 2015-11-01. (Thanks to P Chan.)
Changes to documentation
The zic man page now documents zic's coalescing of transitions
when a zone falls back just before DST springs forward.
Release 2020d - 2020-10-21 11:24:13 -0700
Briefly:
Palestine ends DST earlier than predicted, on 2020-10-24.
Changes to past and future timestamps
Palestine ends DST on 2020-10-24 at 01:00, instead of 2020-10-31
as previously predicted (thanks to Sharef Mustafa.) Its
2019-10-26 fall-back was at 00:00, not 01:00 (thanks to Steffen
Thorsen.) Its 2015-10-23 transition was at 01:00 not 00:00, and
its spring 2020 transition was on March 28 at 00:00, not March 27
(thanks to Pierre Cashon.) This affects Asia/Gaza and
Asia/Hebron. Assume future spring and fall transitions will be on
the Saturday preceding the last Sunday of March and October,
respectively.
Release 2020c - 2020-10-16 11:15:53 -0700
Briefly:
Fiji starts DST later than usual, on 2020-12-20.
Changes to future timestamps
Fiji will start DST on 2020-12-20, instead of 2020-11-08 as
previously predicted. DST will still end on 2021-01-17.
(Thanks to Raymond Kumar and Alan Mintz.) Assume for now that
the later-than-usual start date is a one-time departure from the
recent pattern.
Changes to build procedure
Rearguard tarballs now contain an empty file pacificnew.
Some older downstream software expects this file to exist.
(Problem reported by Mike Cullinan.)
Release 2020b - 2020-10-06 18:35:04 -0700
Briefly:
Revised predictions for Morocco's changes starting in 2023.
Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08.
Macquarie Island has stayed in sync with Tasmania since 2011.
Casey, Antarctica is at +08 in winter and +11 in summer.
zic no longer supports -y, nor the TYPE field of Rules.
Changes to future timestamps
Morocco's spring-forward after Ramadan is now predicted to occur
no sooner than two days after Ramadan, instead of one day.
(Thanks to Milamber.) The first altered prediction is for 2023,
now predicted to spring-forward on April 30 instead of April 23.
Changes to past and future timestamps
Casey Station, Antarctica has been using +08 in winter and +11 in
summer since 2018. The most recent transition from +08 to +11 was
2020-10-04 00:01. Also, Macquarie Island has been staying in
sync with Tasmania since 2011. (Thanks to Steffen Thorsen.)
Changes to past and future time zone abbreviations and DST flags
Canada's Yukon, represented by America/Whitehorse and
America/Dawson, changes its time zone rules from -08/-07 to
permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it.
This change affects only the time zone abbreviation (MST vs PDT)
and daylight saving flag for the period between the two dates.
(Thanks to Andrew G. Smith.)
Changes to past timestamps
Correct several transitions for Hungary for 1918/1983.
For example, the 1983-09-25 fall-back was at 01:00, not 03:00.
(Thanks to Géza Nyáry.) Also, the 1890 transition to standard
time was on 11-01, not 10-01 (thanks to Michael Deckers).
The 1891 French transition was on March 16, not March 15. The
1911-03-11 French transition was at midnight, not a minute later.
Monaco's transitions were on 1892-06-01 and 1911-03-29, not
1891-03-15 and 1911-03-11. (Thanks to Michael Deckers.)
Changes to code
Support for zic's long-obsolete '-y YEARISTYPE' option has been
removed and, with it, so has support for the TYPE field in Rule
lines, which is now reserved for compatibility with earlier zic.
These features were previously deprecated in release 2015f.
(Thanks to Tim Parenti.)
zic now defaults to '-b slim' instead of to '-b fat'.
zic's new '-l -' and '-p -' options uninstall any existing
localtime and posixrules files, respectively.
The undocumented and ineffective tzsetwall function has been
removed.
Changes to build procedure
The Makefile now defaults POSIXRULES to '-', so the posixrules
feature (obsolete as of 2019b) is no longer installed by default.
Changes to documentation and commentary
The long-obsolete files pacificnew, systemv, and yearistype.sh have
been removed from the distribution. (Thanks to Tim Parenti.)
Release 2020a - 2020-04-23 16:03:47 -0700
Briefly:
Morocco springs forward on 2020-05-31, not 2020-05-24.
Canada's Yukon advanced to -07 year-round on 2020-03-08.
America/Nuuk renamed from America/Godthab.
zic now supports expiration dates for leap second lists.
Changes to future timestamps
Morocco's second spring-forward transition in 2020 will be May 31,
not May 24 as predicted earlier. (Thanks to Semlali Naoufal.)
Adjust future-year predictions to use the first Sunday after the
day after Ramadan, not the first Sunday after Ramadan.
Canada's Yukon, represented by America/Whitehorse and
America/Dawson, advanced to -07 year-round, beginning with its
spring-forward transition on 2020-03-08, and will not fall back on
2020-11-01. Although a government press release calls this
"permanent Pacific Daylight Saving Time", we prefer MST for
consistency with nearby Dawson Creek, Creston, and Fort Nelson.
(Thanks to Tim Parenti.)
Changes to past timestamps
Shanghai observed DST in 1919. (Thanks to Phake Nick.)
Changes to timezone identifiers
To reflect current usage in English better, America/Godthab has
been renamed to America/Nuuk. A backwards-compatibility link
remains for the old name.
Changes to code
localtime.c no longer mishandles timestamps after the last
transition in a TZif file with leap seconds and with daylight
saving time transitions projected into the indefinite future.
For example, with TZ='America/Los_Angeles' with leap seconds,
zdump formerly reported a DST transition on 2038-03-14
from 01:59:32.999... to 02:59:33 instead of the correct transition
from 01:59:59.999... to 03:00:00.
zic -L now supports an Expires line in the leapseconds file, and
truncates the TZif output accordingly. This propagates leap
second expiration information into the TZif file, and avoids the
abovementioned localtime.c bug as well as similar bugs present in
many client implementations. If no Expires line is present, zic
-L instead truncates the TZif output based on the #expires comment
present in leapseconds files distributed by tzdb 2018f and later;
however, this usage is obsolescent. For now, the distributed
leapseconds file has an Expires line that is commented out, so
that the file can be fed to older versions of zic which ignore the
commented-out line. Future tzdb distributions are planned to
contain a leapseconds file with an Expires line.
The configuration macros HAVE_TZNAME and USG_COMPAT should now be
set to 1 if the system library supports the feature, and 2 if not.
As before, these macros are nonzero if tzcode should support the
feature, zero otherwise.
The configuration macro ALTZONE now has the same values with the
same meaning as HAVE_TZNAME and USG_COMPAT.
The code's defense against CRLF in leap-seconds.list is now
portable to POSIX awk. (Problem reported by Deborah Goldsmith.)
Although the undocumented tzsetwall function is not changed in
this release, it is now deprecated in preparation for removal in
future releases. Due to POSIX requirements, tzsetwall has not
worked for some time. Any code that uses it should instead use
tzalloc(NULL) or, if portability trumps thread-safety, should
unset the TZ environment variable.
Changes to commentary
The Îles-de-la-Madeleine and the Listuguj reserve are noted as
following America/Halifax, and comments about Yukon's "south" and
"north" have been corrected to say "east" and "west". (Thanks to
Jeffery Nichols.)
Release 2019c - 2019-09-11 08:59:48 -0700
Briefly:
Fiji observes DST from 2019-11-10 to 2020-01-12.
Norfolk Island starts observing Australian-style DST.
Changes to future timestamps
Fiji's next DST transitions will be 2019-11-10 and 2020-01-12
instead of 2019-11-03 and 2020-01-19. (Thanks to Raymond Kumar.)
Adjust future guesses accordingly.
Norfolk Island will observe Australian-style DST starting in
spring 2019. The first transition is on 2019-10-06. (Thanks to
Kyle Czech and Michael Deckers.)
Changes to past timestamps
Many corrections to time in Turkey from 1940 through 1985.
(Thanks to Oya Vulaş via Alois Treindl, and to Kıvanç Yazan.)
The Norfolk Island 1975-03-02 transition was at 02:00 standard
time, not 02:00 DST. (Thanks to Michael Deckers.)
South Korea observed DST from 1948 through 1951. Although this
info was supposed to appear in release 2014j, a typo inadvertently
suppressed the change. (Thanks to Alois Treindl.)
Detroit observed DST in 1967 and 1968 following the US DST rules,
except that its 1967 DST began on June 14 at 00:01. (Thanks to
Alois Treindl for pointing out that the old data entries were
probably wrong.)
Fix several errors in pre-1970 transitions in Perry County, IN.
(Thanks to Alois Treindl for pointing out the 1967/9 errors.)
Edmonton did not observe DST in 1967 or 1969. In 1946 Vancouver
ended DST on 09-29 not 10-13, and Vienna ended DST on 10-07 not
10-06. In 1945 Königsberg (now Kaliningrad) switched from +01/+02
to +02/+03 on 04-10 not 01-01, and its +02/+03 is abbreviated
EET/EEST, not CET/CEST. (Thanks to Alois Treindl.) In 1946
Königsberg switched to +03 on 04-07 not 01-01.
In 1946 Louisville switched from CST to CDT on 04-28 at 00:01, not
01-01 at 00:00. (Thanks to Alois Treindl and Michael Deckers.)
Also, it switched from CST to CDT on 1950-04-30, not 1947-04-27.
The 1892-05-01 transition in Brussels was at 00:17:30, not at noon.
(Thanks to Michael Deckers.)
Changes to past time zone abbreviations and DST flags
Hong Kong Winter Time, observed from 1941-10-01 to 1941-12-25,
is now flagged as DST and is abbreviated HKWT not HKT.
Changes to code
leapseconds.awk now relies only on its input data, rather than
also relying on its comments. (Inspired by code from Dennis
Ferguson and Chris Woodbury.)
The code now defends against CRLFs in leap-seconds.list.
(Thanks to Brian Inglis and Chris Woodbury.)
Changes to documentation and commentary
theory.html discusses leap seconds. (Thanks to Steve Summit.)
Nashville's newspapers dueled about the time of day in the 1950s.
(Thanks to John Seigenthaler.)
Liechtenstein observed Swiss DST in 1941/2.
(Thanks to Alois Treindl.)
Release 2019b - 2019-07-01 00:09:53 -0700
Briefly:
Brazil no longer observes DST.
'zic -b slim' outputs smaller TZif files; please try it out.
Palestine's 2019 spring-forward transition was on 03-29, not 03-30.
Changes to future timestamps
Brazil has canceled DST and will stay on standard time indefinitely.
(Thanks to Steffen Thorsen, Marcus Diniz, and Daniel Soares de
Oliveira.)
Predictions for Morocco now go through 2087 instead of 2037, to
work around a problem on newlib when using TZif files output by
zic 2019a or earlier. (Problem reported by David Gauchard.)
Changes to past and future timestamps
Palestine's 2019 spring transition was 03-29 at 00:00, not 03-30
at 01:00. (Thanks to Sharef Mustafa and Even Scharning.) Guess
future transitions to be March's last Friday at 00:00.
Changes to past timestamps
Hong Kong's 1941-06-15 spring-forward transition was at 03:00, not
03:30. Its 1945 transition from JST to HKT was on 11-18 at 02:00,
not 09-15 at 00:00. In 1946 its spring-forward transition was on
04-21 at 00:00, not the previous day at 03:30. From 1946 through
1952 its fall-back transitions occurred at 04:30, not at 03:30.
In 1947 its fall-back transition was on 11-30, not 12-30.
(Thanks to P Chan.)
Changes to past time zone abbreviations
Italy's 1866 transition to Rome Mean Time was on December 12, not
September 22. This affects only the time zone abbreviation for
Europe/Rome between those dates. (Thanks to Stephen Trainor and
Luigi Rosa.)
Changes affecting metadata only
Add info about the Crimea situation in zone1970.tab and zone.tab.
(Problem reported by Serhii Demediuk.)
Changes to code
zic's new -b option supports a way to control data bloat and to
test for year-2038 bugs in software that reads TZif files.
'zic -b fat' and 'zic -b slim' generate larger and smaller output;
for example, changing from fat to slim shrinks the Europe/London
file from 3648 to 1599 bytes, saving about 56%. Fat and slim
files represent the same set of timestamps and use the same TZif
format as documented in tzfile(5) and in Internet RFC 8536.
Fat format attempts to work around bugs or incompatibilities in
older software, notably software that mishandles 64-bit TZif data
or uses obsolete TZ strings like "EET-2EEST" that lack DST rules.
Slim format is more efficient and does not work around 64-bit bugs
or obsolete TZ strings. Currently zic defaults to fat format
unless you compile with -DZIC_BLOAT_DEFAULT=\"slim\"; this
out-of-the-box default is intended to change in future releases
as the buggy software often mishandles timestamps anyway.
zic no longer treats a set of rules ending in 2037 specially.
Previously, zic assumed that such a ruleset meant that future
timestamps could not be predicted, and therefore omitted a
POSIX-like TZ string in the TZif output. The old behavior is no
longer needed for current tzdata, and caused problems with newlib
when used with older tzdata (reported by David Gauchard).
zic no longer generates some artifact transitions. For example,
Europe/London no longer has a no-op transition in January 1996.
Changes to build procedure
tzdata.zi now assumes zic 2017c or later. This shrinks tzdata.zi
by a percent or so.
Changes to documentation and commentary
The Makefile now documents the POSIXRULES macro as being obsolete,
and similarly, zic's -p POSIXRULES option is now documented as
being obsolete. Although the POSIXRULES feature still exists and
works as before, in practice it is rarely used for its intended
purpose, and it does not work either in the default reference
implementation (for timestamps after 2037) or in common
implementations such as GNU/Linux (for contemporary timestamps).
Since POSIXRULES was designed primarily as a temporary transition
facility for System V platforms that died off decades ago, it is
being decommissioned rather than institutionalized.
New info on Bonin Islands and Marcus (thanks to Wakaba and Phake Nick).
Release 2019a - 2019-03-25 22:01:33 -0700
Briefly:
Palestine "springs forward" on 2019-03-30 instead of 2019-03-23.
Metlakatla "fell back" to rejoin Alaska Time on 2019-01-20 at 02:00.
Changes to past and future timestamps
Palestine will not start DST until 2019-03-30, instead of 2019-03-23 as
previously predicted. Adjust our prediction by guessing that spring
transitions will be between 24 and 30 March, which matches recent practice
since 2016. (Thanks to Even Scharning and Tim Parenti.)
Metlakatla ended its observance of Pacific standard time,
rejoining Alaska Time, on 2019-01-20 at 02:00. (Thanks to Ryan
Stanley and Tim Parenti.)
Changes to past timestamps
Israel observed DST in 1980 (08-02/09-13) and 1984 (05-05/08-25).
(Thanks to Alois Treindl and Isaac Starkman.)
Changes to time zone abbreviations
Etc/UCT is now a backward-compatibility link to Etc/UTC, instead
of being a separate zone that generates the abbreviation "UCT",
which nowadays is typically a typo. (Problem reported by Isiah
Meadows.)
Changes to code
zic now has an -r option to limit the time range of output data.
For example, 'zic -r @1000000000' limits the output data to
timestamps starting 1000000000 seconds after the Epoch.
This helps shrink output size and can be useful for applications
not needing the full timestamp history, such as TZDIST truncation;
see Internet RFC 8536 section 5.1. (Inspired by a feature request
from Christopher Wong, helped along by bug reports from Wong and
from Tim Parenti.)
Changes to documentation
Mention Internet RFC 8536 (February 2019), which documents TZif.
tz-link.html now cites tzdata-meta
<https://tzdata-meta.timtimeonline.com/>.
Release 2018i - 2018-12-30 11:05:43 -0800
Briefly:
São Tomé and Príncipe switches from +01 to +00 on 2019-01-01.
Changes to future timestamps
Due to a change in government, São Tomé and Príncipe switches back
from +01 to +00 on 2019-01-01 at 02:00. (Thanks to Vadim
Nasardinov and Michael Deckers.)
Release 2018h - 2018-12-23 17:59:32 -0800
Briefly:
Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21.
New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move.
Metlakatla, Alaska observes PST this winter only.
Guess Morocco will continue to adjust clocks around Ramadan.
Add predictions for Iran from 2038 through 2090.
Changes to future timestamps
Guess that Morocco will continue to fall back just before and
spring forward just after Ramadan, the practice since 2012.
(Thanks to Maamar Abdelkader.) This means Morocco will observe
negative DST during Ramadan in main and vanguard formats, and in
rearguard format it stays in the +00 timezone and observes
ordinary DST in all months other than Ramadan. As before, extend
this guesswork to the year 2037. As a consequence, Morocco is
scheduled to observe three DST transitions in some Gregorian years
(e.g., 2033) due to the mismatch between the Gregorian and Islamic
calendars.
The table of exact transitions for Iranian DST has been extended.
It formerly cut off before the year 2038 in a nod to 32-bit time_t.
It now cuts off before 2091 as there is doubt about how the Persian
calendar will treat 2091. This change predicts DST transitions in
2038-9, 2042-3, and 2046-7 to occur one day later than previously
predicted. As before, post-cutoff transitions are approximated.
Changes to past and future timestamps
Qyzylorda (aka Kyzylorda) oblast in Kazakhstan moved from +06 to
+05 on 2018-12-21. This is a zone split as Qostanay (aka
Kostanay) did not switch, so create a zone Asia/Qostanay.
Metlakatla moved from Alaska to Pacific standard time on 2018-11-04.
It did not change clocks that day and remains on -08 this winter.
(Thanks to Ryan Stanley.) It will revert to the usual Alaska
rules next spring, so this change affects only timestamps
from 2018-11-04 through 2019-03-10.
Change to past timestamps
Kwajalein's 1993-08-20 transition from -12 to +12 was at 24:00,
not 00:00. I transcribed the time incorrectly from Shanks.
(Thanks to Phake Nick.)
Nauru's 1979 transition was on 02-10 at 02:00, not 05-01 at 00:00.
(Thanks to Phake Nick.)
Guam observed DST irregularly from 1959 through 1977.
(Thanks to Phake Nick.)
Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on
10-01 changed standard time to +08:30 (not +08). Its transition
back to +08 after WWII was on 1945-09-15, not the previous day.
Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT).
(Thanks to Phake Nick, Steve Allen, and Joseph Myers.) Also,
its 1952 fallback was on 11-02 (not 10-25).
This release contains many changes to timestamps before 1946 due
to Japanese possession or occupation of Pacific/Chuuk,
Pacific/Guam, Pacific/Kosrae, Pacific/Kwajalein, Pacific/Majuro,
Pacific/Nauru, Pacific/Palau, and Pacific/Pohnpei.
(Thanks to Phake Nick.)
Assume that the Spanish East Indies was like the Philippines and
observed American time until the end of 1844. This affects
Pacific/Chuuk, Pacific/Kosrae, Pacific/Palau, and Pacific/Pohnpei.
Changes to past tm_isdst flags
For the recent Morocco change, the tm_isdst flag should be 1 from
2018-10-27 00:00 to 2018-10-28 03:00. (Thanks to Michael Deckers.)
Give a URL to the official decree. (Thanks to Matt Johnson.)
Release 2018g - 2018-10-26 22:22:45 -0700
Briefly:
Morocco switches to permanent +01 on 2018-10-28.
Changes to future timestamps
Morocco switches from +00/+01 to permanent +01 effective 2018-10-28,
so its clocks will not fall back as previously scheduled.
(Thanks to Mohamed Essedik Najd and Brian Inglis.)
Changes to code
When generating TZif files with leap seconds, zic no longer uses a
format that trips up older 32-bit clients, fixing a bug introduced
in 2018f. (Reported by Daniel Fischer.) Also, the zic workaround
for QTBUG-53071 now also works for TZif files with leap seconds.
The translator to rearguard format now rewrites the line
"Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to
"Rule Japan 1948 1951 - Sep Sun>=9 1:00 0 S".
This caters to zic before 2007 and to Oracle TZUpdater 2.2.0
and earlier. (Reported by Christos Zoulas.)
Changes to past time zone abbreviations
Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii.
This reverts to 2011h, as the abbreviation change in 2011i was
likely inadvertent.
Changes to documentation
tzfile.5 has new sections on interoperability issues.
Release 2018f - 2018-10-18 00:14:18 -0700
Briefly:
Volgograd moves from +03 to +04 on 2018-10-28.
Fiji ends DST 2019-01-13, not 2019-01-20.
Most of Chile changes DST dates, effective 2019-04-06.
Changes to future timestamps
Volgograd moves from +03 to +04 on 2018-10-28 at 02:00.
(Thanks to Alexander Fetisov and Stepan Golosunov.)
Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously
predicted. (Thanks to Raymond Kumar.) Adjust future predictions
accordingly.
Most of Chile will end DST on the first Saturday in April at 24:00 mainland
time, and resume DST on the first Saturday in September at 24:00 mainland
time. The changes are effective from 2019-04-06, and do not affect the
Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa
and Tim Parenti.) Adjust future predictions accordingly.
Changes to past timestamps
The 2018-05-05 North Korea 30-minute time zone change took place
at 23:30 the previous day, not at 00:00 that day.
China's 1988 spring-forward transition was on April 17, not
April 10. Its DST transitions in 1986/91 were at 02:00, not 00:00.
(Thanks to P Chan.)
Fix several issues for Macau before 1992. Macau's pre-1904 LMT
was off by 10 s. Macau switched to +08 in 1904 not 1912, and
temporarily switched to +09/+10 during World War II. Macau
observed DST in 1942/79, not 1961/80, and there were several
errors for transition times and dates. (Thanks to P Chan.)
The 1948-1951 fallback transitions in Japan were at 25:00 on
September's second Saturday, not at 24:00. (Thanks to Phake Nick.)
zic turns this into 01:00 on the day after September's second
Saturday, which is the best that POSIX or C platforms can do.
Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014
paper by Li Yu, replacing more-questionable data from Shanks.
Changes to time zone abbreviations
Use "PST" and "PDT" for Philippine time. (Thanks to Paul Goyette.)
Changes to code
zic now always generates TZif files where time type 0 is used for
timestamps before the first transition. This simplifies the
reading of TZif files and should not affect behavior of existing
TZif readers because the same set of time types is used; only
their internal indexes may have changed. This affects only the
legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
EET, which previously used nonzero types for these timestamps.
Because of the type 0 change, zic no longer outputs a dummy
transition at time -2**59 (before the Big Bang), as clients should
no longer need this to handle historical timestamps correctly.
This reverts a change introduced in 2013d and shrinks most TZif
files by a few bytes.
zic now supports negative time-of-day in Rule and Leap lines, e.g.,
"Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
occurs at 18:00 on the Saturday before the last Sunday in April.
This behavior was documented in 2018a but the code did not
entirely match the documentation.
localtime.c no longer requires at least one time type in TZif
files that lack transitions or have a POSIX-style TZ string. This
future-proofs the code against possible future extensions to the
format that would allow TZif files with POSIX-style TZ strings and
without transitions or time types.
A read-access subscript error in localtime.c has been fixed.
It could occur only in TZif files with timecnt == 0, something that
does not happen in practice now but could happen in future versions.
localtime.c no longer ignores TZif POSIX-style TZ strings that
specify only standard time. Instead, these TZ strings now
override the default time type for timestamps after the last
transition (or for all timestamps if there are no transitions),
just as DST strings specifying DST have always done.
leapseconds.awk now outputs "#updated" and "#expires" comments,
and supports leap seconds at the ends of months other than June
and December. (Inspired by suggestions from Chris Woodbury.)
Changes to documentation
New restrictions: A Rule name must start with a character that
is neither an ASCII digit nor "-" nor "+", and an unquoted name
should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
The latter restriction makes room for future extensions (a
possibility noted by Tom Lane).
tzfile.5 now documents what time types apply before the first and
after the last transition, if any.
Documentation now uses the spelling "timezone" for a TZ setting
that determines timestamp history, and "time zone" for a
geographic region currently sharing the same standard time.
The name "TZif" is now used for the tz binary data format.
tz-link.htm now mentions the A0 TimeZone Migration utilities.
(Thanks to Aldrin Martoq for the link.)
Changes to build procedure
New 'make' target 'rearguard_tarballs' to build the rearguard
tarball only. This is a convenience on platforms that lack lzip
if you want to build the rearguard tarball. (Problem reported by
Deborah Goldsmith.)
tzdata.zi is now more stable from release to release. (Problem
noted by Tom Lane.) It is also a bit shorter.
tzdata.zi now can contain comment lines documenting configuration
information, such as which data format was selected, which input
files were used, and how leap seconds are treated. (Problems
noted by Lester Caine and Brian Inglis.) If the Makefile defaults
are used these comment lines are absent, for backward
compatibility. A redistributor intending to alter its copy of the
files should also append "-LABEL" to the 'version' file's first
line, where "LABEL" identifies the redistributor's change.
Release 2018e - 2018-05-01 23:42:51 -0700
Briefly:
North Korea switches back to +09 on 2018-05-05.
The main format uses negative DST again, for Ireland etc.
'make tarballs' now also builds a rearguard tarball.
New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines.
Changes to past and future timestamps
North Korea switches back from +0830 to +09 on 2018-05-05.
(Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon,
and Tim Parenti.)
Bring back the negative-DST changes of 2018a, except be more
compatible with data parsers that do not support negative DST.
Also, this now affects historical timestamps in Namibia and the
former Czechoslovakia, not just Ireland. The main format now uses
negative DST to model timestamps in Europe/Dublin (from 1971 on),
Europe/Prague (1946/7), and Africa/Windhoek (1994/2017). This
does not affect UT offsets, only time zone abbreviations and the
tm_isdst flag. Also, this does not affect rearguard or vanguard
formats; effectively the main format now uses vanguard instead of
rearguard format. Data parsers that do not support negative DST
can still use data from the rearguard tarball described below.
Changes to build procedure
The command 'make tarballs' now also builds the tarball
tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz
except that it uses rearguard format intended for trailing-edge
data parsers.
Changes to data format and to code
The SAVE column of Rule and Zone lines can now have an 's' or 'd'
suffix, which specifies whether the adjusted time is standard time
or daylight saving time. If no suffix is given, daylight saving
time is used if and only if the SAVE column is nonzero; this is
the longstanding behavior. Although this new feature is not used
in tzdata, it could be used to specify the legal time in Namibia
1994-2017, as opposed to the popular time (see below).
Changes to past timestamps
From 1994 through 2017 Namibia observed DST in winter, not summer.
That is, it used negative DST, as Ireland still does. This change
does not affect UTC offsets; it affects only the tm_isdst flag and
the abbreviation used during summer, which is now CAT, not WAST.
Although (as noted by Michael Deckers) summer and winter time were
both simply called "standard time" in Namibian law, in common
practice winter time was considered to be DST (as noted by Stephen
Colebourne). The full effect of this change is only in vanguard
and main format; in rearguard format, the tm_isdst flag is still
zero in winter and nonzero in summer.
In 1946/7 Czechoslovakia also observed negative DST in winter.
The full effect of this change is only in vanguard and main
formats; in rearguard format, it is modeled as plain GMT without
daylight saving. Also, the dates of some 1944/5 DST transitions
in Czechoslovakia have been changed.
Release 2018d - 2018-03-22 07:05:46 -0700
Briefly:
Palestine starts DST a week earlier in 2018.
Add support for vanguard and rearguard data consumers.
Add subsecond precision to source data format, though not to data.
Changes to future timestamps
In 2018, Palestine starts DST on March 24, not March 31.
Adjust future predictions accordingly. (Thanks to Sharef Mustafa.)
Changes to past and future timestamps
Casey Station in Antarctica changed from +11 to +08 on 2018-03-11
at 04:00. (Thanks to Steffen Thorsen.)
Changes to past timestamps
Historical transitions for Uruguay, represented by
America/Montevideo, have been updated per official legal documents,
replacing previous data mainly originating from the inventions of
Shanks & Pottenger. This has resulted in adjustments ranging from
30 to 90 minutes in either direction over at least two dozen
distinct periods ranging from one day to several years in length.
A mere handful of pre-1991 transitions are unaffected; data since
then has come from more reliable contemporaneous reporting. These
changes affect various timestamps in 1920-1923, 1936, 1939,
1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990.
Additionally, Uruguay's pre-standard-time UT offset has been
adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to
match the location of the Observatory of the National Meteorological
Institute in Montevideo.
(Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.)
East Kiribati skipped New Year's Eve 1994, not New Year's Day 1995.
(Thanks to Kerry Shetline.)
Fix the 1912-01-01 transition for Portugal and its colonies.
This transition was at 00:00 according to the new UT offset, not
according to the old one. Also assume that Cape Verde switched on
the same date as the rest, not in 1907. This affects
Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores,
Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon.
(Thanks to Michael Deckers.)
Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in
Turks & Caicos.
Changes to past time zone abbreviations
MMT took effect in Uruguay from 1908-06-10, not 1898-06-28. There
is no clock change associated with the transition.
Changes to build procedure
The new DATAFORM macro in the Makefile lets the installer choose
among three source data formats. The idea is to lessen downstream
disruption when data formats are improved.
* DATAFORM=vanguard installs from the latest, bleeding-edge
format. DATAFORM=main (the default) installs from the format
used in the 'africa' etc. files. DATAFORM=rearguard installs
from a trailing-edge format. Eventually, elements of today's
vanguard format should move to the main format, and similarly
the main format's features should eventually move to the
rearguard format.
* In the current version, the main and rearguard formats are
identical and match that of 2018c, so this change does not
affect default behavior. The vanguard format currently contains
one feature not in the main format: negative SAVE values. This
improves support for Ireland, which uses Irish Standard Time
(IST, UTC+01) in summer and GMT (UTC) in winter. tzcode has
supported negative SAVE values for decades, and this feature
should move to the main format soon. However, it will not move
to the rearguard format for quite some time because some
downstream parsers do not support it.
* The build procedure constructs three files vanguard.zi, main.zi,
and rearguard.zi, one for each format. Although the files
represent essentially the same data, they may have minor
discrepancies that users are not likely to notice. The files
are intended for downstream data consumers and are not
installed. Zoneinfo parsers that do not support negative SAVE values
should start using rearguard.zi, so that they will be unaffected
when the negative-DST feature moves from vanguard to main.
Bleeding-edge Zoneinfo parsers that support the new features
already can use vanguard.zi; in this respect, current tzcode is
bleeding-edge.
The Makefile should now be safe for parallelized builds, and 'make
-j to2050new.tzs' is now much faster on a multiprocessor host
with GNU Make.
When built with -DSUPPRESS_TZDIR, the tzcode library no longer
prepends TZDIR/ to file names that do not begin with '/'. This is
not recommended for general use, due to its security implications.
(From a suggestion by Manuela Friedrich.)
Changes to code
zic now accepts subsecond precision in expressions like
00:19:32.13, which is approximately the legal time of the
Netherlands from 1835 to 1937. However, because it is
questionable whether the few recorded uses of non-integer offsets
had subsecond precision in practice, there are no plans for tzdata
to use this feature. (Thanks to Steve Allen for pointing out
the limitations of historical data in this area.)
The code is a bit more portable to MS-Windows. Installers can
compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that
reserve identifiers like 'localtime'. (Thanks to Manuela
Friedrich.)
Changes to documentation and commentary
theory.html now outlines tzdb's extensions to POSIX's model for
civil time, and has a section "POSIX features no longer needed"
that lists POSIX API components that are now vestigial.
(From suggestions by Steve Summit.) It also better distinguishes
time zones from tz regions. (From a suggestion by Guy Harris.)
Commentary is now more consistent about using the phrase "daylight
saving time", to match the C name tm_isdst. Daylight saving time
need not occur in summer, and need not have a positive offset from
standard time.
Commentary about historical transitions in Uruguay has been expanded
with links to many relevant legal documents.
(Thanks to Tim Parenti.)
Commentary now uses some non-ASCII characters with Unicode value
less than U+0100, as they can be useful and should work even with
older editors such as XEmacs.
Release 2018c - 2018-01-22 23:00:44 -0800
Briefly:
Revert Irish changes that relied on negative SAVE values.
Changes to tm_isdst
Revert the 2018a change to Europe/Dublin. As before, this change
does not affect UT offsets or abbreviations; it affects only
whether timestamps are considered to be standard time or
daylight-saving time, as expressed in the tm_isdst flag of C's
struct tm type. This reversion is intended to be a temporary
workaround for problems discovered with downstream uses of
releases 2018a and 2018b, which implemented Irish time by using
negative SAVE values in the Eire rules of the 'europe' file.
Although negative SAVE values have been part of tzcode for many
years and are supported by many platforms, they were not
documented before 2018a and ICU and OpenJDK do not currently
support them. A mechanism to export data to platforms lacking
support for negative DST is planned to be developed before the
change is reapplied. (Problems reported by Deborah Goldsmith and
Stephen Colebourne.)
Changes to past timestamps
Japanese DST transitions (1948-1951) were Sundays at 00:00, not
Saturdays or Sundays at 02:00. (Thanks to Takayuki Nikai.)
Changes to build procedure
The build procedure now works around mawk 1.3.3's lack of support
for character class expressions. (Problem reported by Ohyama.)
Release 2018b - 2018-01-17 23:24:48 -0800
Briefly:
Fix a packaging problem in tz2018a, which was missing 'pacificnew'.
Changes to build procedure
The distribution now contains the file 'pacificnew' again.
This file was inadvertently omitted in the 2018a distribution.
(Problem reported by Matias Fonzo.)
Release 2018a - 2018-01-12 22:29:21 -0800
Briefly:
São Tomé and Príncipe switched from +00 to +01.
Brazil's DST will now start on November's first Sunday.
Ireland's standard time is now in the summer, not the winter.
Use Debian-style installation locations, instead of 4.3BSD-style.
New zic option -t.
Changes to past and future timestamps
São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at
01:00. (Thanks to Steffen Thorsen and Michael Deckers.)
Changes to future timestamps
Starting in 2018 southern Brazil will begin DST on November's
first Sunday instead of October's third Sunday. (Thanks to
Steffen Thorsen.)
Changes to past timestamps
A discrepancy of 4 s in timestamps before 1931 in South Sudan has
been corrected. The 'backzone' and 'zone.tab' files did not agree
with the 'africa' and 'zone1970.tab' files. (Problem reported by
Michael Deckers.)
The abbreviation invented for Bolivia Summer Time (1931-2) is now
BST instead of BOST, to be more consistent with the convention
used for Latvian Summer Time (1918-9) and for British Summer Time.
Changes to tm_isdst
Change Europe/Dublin so that it observes Irish Standard Time (UT
+01) in summer and GMT (as negative daylight-saving) in winter,
instead of observing standard time (GMT) in winter and Irish
Summer Time (UT +01) in summer. This change does not affect UT
offsets or abbreviations; it affects only whether timestamps are
considered to be standard time or daylight-saving time, as
expressed in the tm_isdst flag of C's struct tm type.
(Discrepancy noted by Derick Rethans.)
Changes to build procedure
The default installation locations have been changed to mostly
match Debian circa 2017, instead of being designed as an add-on to
4.3BSD circa 1986. This affects the Makefile macros TOPDIR,
TZDIR, MANDIR, and LIBDIR. New Makefile macros TZDEFAULT, USRDIR,
USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor
locations more precisely. (This responds to suggestions from
Brian Inglis and from Steve Summit.)
The default installation procedure no longer creates the
backward-compatibility link US/Pacific-New, which causes
confusion during user setup (e.g., see Debian bug 815200).
Use 'make BACKWARD="backward pacificnew"' to create the link
anyway, for now. Eventually we plan to remove the link entirely.
tzdata.zi now contains a version-number comment.
(Suggested by Tom Lane.)
The Makefile now quotes values like BACKWARD more carefully when
passing them to the shell. (Problem reported by Zefram.)
Builders no longer need to specify -DHAVE_SNPRINTF on platforms
that have snprintf and use pre-C99 compilers. (Problem reported
by Jon Skeet.)
Changes to code
zic has a new option -t FILE that specifies the location of the
file that determines local time when TZ is unset. The default for
this location can be configured via the new TZDEFAULT makefile
macro, which defaults to /etc/localtime.
Diagnostics and commentary now distinguish UT from UTC more
carefully; see theory.html for more information about UT vs UTC.
zic has been ported to GCC 8's -Wstringop-truncation option.
(Problem reported by Martin Sebor.)
Changes to documentation and commentary
The zic man page now documents the longstanding behavior that
times and years can be out of the usual range, with negative times
counting backwards from midnight and with year 0 preceding year 1.
(Problem reported by Michael Deckers.)
The theory.html file now mentions the POSIX limit of six chars
per abbreviation, and lists alphabetic abbreviations used.
The files tz-art.htm and tz-link.htm have been renamed to
tz-art.html and tz-link.html, respectively, for consistency with
other file names and to simplify web server configuration.
Release 2017c - 2017-10-20 14:49:34 -0700
Briefly:
Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
Fiji ends DST 2018-01-14, not 2018-01-21.
Namibia switches from +01/+02 to +02 on 2018-04-01.
Sudan switches from +03 to +02 on 2017-11-01.
Tonga likely switches from +13/+14 to +13 on 2017-11-05.
Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
A new file tzdata.zi now holds a small text copy of all data.
The zic input format has been regularized slightly.
Changes to future timestamps
Northern Cyprus has decided to resume EU rules starting
2017-10-29, thus reinstituting winter time.
Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously
predicted. (Thanks to Dominic Fok.) Adjust future predictions
accordingly.
Namibia will switch from +01 with DST to +02 all year on
2017-09-03 at 02:00. This affects UT offsets starting 2018-04-01
at 02:00. (Thanks to Steffen Thorsen.)
Sudan will switch from +03 to +02 on 2017-11-01. (Thanks to Ahmed
Atyya and Yahia Abdalla.) South Sudan is not switching, so
Africa/Juba is no longer a link to Africa/Khartoum.
Tonga has likely ended its experiment with DST, and will not
adjust its clocks on 2017-11-05. Although Tonga has not announced
whether it will continue to observe DST, the IATA is assuming that
it will not. (Thanks to David Wade.)
Turks & Caicos will switch from -04 all year to -05 with US DST on
2018-03-11 at 03:00. This affects UT offsets starting 2018-11-04
at 02:00. (Thanks to Steffen Thorsen.)
Changes to past timestamps
Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03.
(Thanks to Arthur David Olson.)
Detroit did not observe DST in 1967.
Use railway time for Asia/Kolkata before 1941, by switching to
Madras local time (UT +052110) in 1870, then to IST (UT +0530) in
1906. Also, treat 1941-2's +0630 as DST, like 1942-5.
Europe/Dublin's 1946 and 1947 fallback transitions occurred at
02:00 standard time, not 02:00 DST. (Thanks to Michael Deckers.)
Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to
American time in 1892, not 1879. (Thanks to Michael Deckers.)
Adjust the 1867 transition in Alaska to better reflect the
historical record, by changing it to occur on 1867-10-18 at 15:30
Sitka time rather than at the start of 1867-10-17 local time.
Although strictly speaking this is accurate only for Sitka,
the rest of Alaska's blanks need to be filled in somehow.
Fix off-by-one errors in UT offsets for Adak and Nome before 1867.
(Thanks to Michael Deckers.)
Add 7 s to the UT offset in Asia/Yangon before 1920.
Changes to zone names
Remove Canada/East-Saskatchewan from the 'backward' file, as it
exceeded the 14-character limit and was an unused misnomer anyway.
Changes to build procedure
To support applications that prefer to read time zone data in text
form, two zic input files tzdata.zi and leapseconds are now
installed by default. The commands 'zic tzdata.zi' and 'zic -L
leapseconds tzdata.zi' can reproduce the tzdata binary files
without and with leap seconds, respectively. To prevent these two
new files from being installed, use 'make TZDATA_TEXT=', and to
suppress leap seconds from the tzdata text installation, use 'make
TZDATA_TEXT=tzdata.zi'.
'make BACKWARD=' now suppresses backward-compatibility names
like 'US/Pacific' that are defined in the 'backward' and
'pacificnew' files.
'make check' now works on systems that lack a UTF-8 locale,
or that lack the nsgmls program. Set UTF8_LOCALE to configure
the name of a UTF-8 locale, if you have one.
Y2K runtime checks are no longer enabled by default. Add
-DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of
adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
to disable them. (New name suggested by Brian Inglis.)
The build procedure for zdump now works on AIX 7.1.
(Problem reported by Kees Dekker.)
Changes to code
zic and the reference runtime now reject multiple leap seconds
within 28 days of each other, or leap seconds before the Epoch.
As a result, support for double leap seconds, which was
obsolescent and undocumented, has been removed. Double leap
seconds were an error in the C89 standard; they have never existed
in civil timekeeping. (Thanks to Robert Elz and Bradley White for
noticing glitches in the code that uncovered this problem.)
zic now warns about use of the obsolescent and undocumented -y
option, and about use of the obsolescent TYPE field of Rule lines.
zic now allows unambiguous abbreviations like "Sa" and "Su" for
weekdays; formerly it rejected them due to a bug. Conversely, zic
no longer considers non-prefixes to be abbreviations; for example,
it no longer accepts "lF" as an abbreviation for "lastFriday".
Also, zic warns about the undocumented usage with a "last-"
prefix, e.g., "last-Fri".
Similarly, zic now accepts the unambiguous abbreviation "L" for
"Link" in ordinary context and for "Leap" in leap-second context.
Conversely, zic no longer accepts non-prefixes such as "La" as
abbreviations for words like "Leap".
zic no longer accepts leap second lines in ordinary input, or
ordinary lines in leap second input. Formerly, zic sometimes
warned about this undocumented usage and handled it incorrectly.
The new macro HAVE_TZNAME governs whether the tzname external
variable is exported, instead of USG_COMPAT. USG_COMPAT now
governs only the external variables "timezone" and "daylight".
This change is needed because the three variables are not in the
same category: although POSIX requires tzname, it specifies the
other two variables as optional. Also, USG_COMPAT is now 1 or 0:
if not defined, the code attempts to guess it from other macros.
localtime.c and difftime.c no longer require stdio.h, and .c files
other than zic.c no longer require sys/wait.h.
zdump.c no longer assumes snprintf. (Reported by Jonathan Leffler.)
Calculation of time_t extrema works around a bug in GCC 4.8.4
(Reported by Stan Shebs and Joseph Myers.)
zic.c no longer mistranslates formats of line numbers in non-English
locales. (Problem reported by Benno Schulenberg.)
Several minor changes have been made to the code to make it a
bit easier to port to MS-Windows and Solaris. (Thanks to Kees
Dekker for reporting the problems.)
Changes to documentation and commentary
The two new files 'theory.html' and 'calendars' contain the
contents of the removed file 'Theory'. The goal is to document
tzdb theory more accessibly.
The zic man page now documents abbreviation rules.
tz-link.htm now covers how to apply tzdata changes to clients.
(Thanks to Jorge Fábregas for the AIX link.) It also mentions MySQL.
The leap-seconds.list URL has been updated to something that is
more reliable for tzdb. (Thanks to Tim Parenti and Brian Inglis.)
Release 2017b - 2017-03-17 07:30:38 -0700
Briefly: Haiti has resumed DST.
Changes to past and future timestamps
Haiti resumed observance of DST in 2017. (Thanks to Steffen Thorsen.)
Changes to past timestamps
Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.
Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
is one byte over the POSIX limit. (Problem reported by Derick Rethans.)
Changes to code
The reference localtime implementation now falls back on the
current US daylight-saving transition rules rather than the
1987-2006 rules. This fallback occurs only when (1) the TZ
environment variable has a value like "AST4ADT" that asks
for daylight saving time but does not specify the rules, (2) there
is no file by that name, and (3) the TZDEFRULES file cannot be
loaded. (Thanks to Tom Lane.)
Release 2017a - 2017-02-28 00:05:36 -0800
Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
discontinues DST.
Changes to future timestamps
Mongolia no longer observes DST. (Thanks to Ganbold Tsagaankhuu.)
Chile's Region of Magallanes moves from -04/-03 to -03 year-round.
Its clocks diverge from America/Santiago starting 2017-05-13 at
23:00, hiving off a new zone America/Punta_Arenas. Although the
Chilean government says this change expires in May 2019, for now
assume it's permanent. (Thanks to Juan Correa and Deborah
Goldsmith.) This also affects Antarctica/Palmer.
Changes to past timestamps
Fix many entries for historical timestamps for Europe/Madrid
before 1979, to agree with tables compiled by Pere Planesas of the
National Astronomical Observatory of Spain. As a side effect,
this changes some timestamps for Africa/Ceuta before 1929, which
are probably guesswork anyway. (Thanks to Steve Allen and
Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for
correcting the 1901 transition.)
Ecuador observed DST from 1992-11-28 to 1993-02-05.
(Thanks to Alois Treindl.)
Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21.
(Thanks to Stepan Golosunov.)
Changes to past and future time zone abbreviations
Switch to numeric time zone abbreviations for South America, as
part of the ongoing project of removing invented abbreviations.
This avoids the need to invent an abbreviation for the new Chilean
new zone. Similarly, switch from invented to numeric time zone
abbreviations for Afghanistan, American Samoa, the Azores,
Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei,
Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is,
Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland,
Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia,
the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia,
Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau,
Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St
Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore,
Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and
Xinjiang; for 20-minute daylight saving time in Ghana before 1943;
for half-hour daylight saving time in Belize before 1944 and in
the Dominican Republic before 1975; and for Canary Islands before
1946, for Guinea-Bissau before 1975, for Iceland before 1969, for
Indian Summer Time before 1942, for Indonesia before around 1964,
for Kenya before 1960, for Liberia before 1973, for Madeira before
1967, for Namibia before 1943, for the Netherlands in 1937-9, for
Pakistan before 1971, for Western Sahara before 1977, and for
Zaporozhye in 1880-1924.
For Alaska time from 1900 through 1967, instead of "CAT" use the
abbreviation "AST", the abbreviation commonly used at the time
(Atlantic Standard Time had not been standardized yet). Use "AWT"
and "APT" instead of the invented abbreviations "CAWT" and "CAPT".
Use "CST" and "CDT" instead of invented abbreviations for Macau
before 1999 and Taiwan before 1938, and use "JST" instead of the
invented abbreviation "JCST" for Japan and Korea before 1938.
Change to database entry category
Move the Pacific/Johnston link from 'australasia' to 'backward',
since Johnston is now uninhabited.
Changes to code
zic no longer mishandles some transitions in January 2038 when it
attempts to work around Qt bug 53071. This fixes a bug affecting
Pacific/Tongatapu that was introduced in zic 2016e. localtime.c
now contains a workaround, useful when loading a file generated by
a buggy zic. (Problem and localtime.c fix reported by Bradley
White.)
zdump -i now outputs non-hour numeric time zone abbreviations
without a colon, e.g., "+0530" rather than "+05:30". This agrees
with zic %z and with common practice, and simplifies auditing of
zdump output.
zdump is now buildable again with -DUSE_LTZ=0.
(Problem reported by Joseph Myers.)
zdump.c now always includes private.h, to avoid code duplication
with private.h. (Problem reported by Kees Dekker.)
localtime.c no longer mishandles early or late timestamps
when TZ is set to a POSIX-style string that specifies DST.
(Problem reported by Kees Dekker.)
date and strftime now cause %z to generate "-0000" instead of
"+0000" when the UT offset is zero and the time zone abbreviation
begins with "-".
Changes to documentation and commentary
The 'Theory' file now better documents choice of historical time
zone abbreviations. (Problems reported by Michael Deckers.)
tz-link.htm now covers leap smearing, which is popular in clouds.
Release 2016j - 2016-11-22 23:17:13 -0800
Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.
Changes to future timestamps
Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00.
This hives off a new zone Europe/Saratov from Europe/Volgograd.
(Thanks to Yuri Konotopov and Stepan Golosunov.)
Changes to past timestamps
The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
1999, not fall 1994. (Thanks to Stepan Golosunov.)
Changes to past time zone abbreviations
Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote
summer time before 1948. The old use of "EET" was a typo.
Changes to code
zic no longer mishandles file systems that lack hard links, fixing
bugs introduced in 2016g. (Problems reported by Tom Lane.)
Also, when the destination already contains symbolic links, zic
should now work better on systems where the 'link' system call
does not follow symbolic links.
Changes to documentation and commentary
tz-link.htm now documents the relationship between release version
numbers and development-repository commit tags. (Suggested by
Paul Koning.)
The 'Theory' file now documents UT.
iso3166.tab now accents "Curaçao", and commentary now mentions
the names "Cabo Verde" and "Czechia". (Thanks to Jiří Boháč.)
Release 2016i - 2016-11-01 23:19:52 -0700
Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga
reintroduces DST on 2016-11-06.
Changes to future timestamps
Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on
2017-01-15 at 03:00. Assume future observances in Tonga will be
from the first Sunday in November through the third Sunday in
January, like Fiji. (Thanks to Pulu ʻAnau.) Switch to numeric
time zone abbreviations for this zone.
Changes to past and future timestamps
Northern Cyprus is now +03 year round, causing a split in Cyprus
time zones starting 2016-10-30 at 04:00. This creates a zone
Asia/Famagusta. (Thanks to Even Scharning and Matt Johnson.)
Antarctica/Casey switched from +08 to +11 on 2016-10-22.
(Thanks to Steffen Thorsen.)
Changes to past timestamps
Several corrections were made for pre-1975 timestamps in Italy.
These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and
Europe/Vatican.
First, the 1893-11-01 00:00 transition in Italy used the new UT
offset (+01), not the old (+00:49:56). (Thanks to Michael
Deckers.)
Second, rules for daylight saving in Italy were changed to agree
with Italy's National Institute of Metrological Research (INRiM)
except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian
Inglis, and Michael Deckers):
The 1916-06-03 transition was at 24:00, not 00:00.
The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at
00:00, not 01:00.
The 1917-09-30 and 1918-10-06 transitions were at 24:00, not
01:00.
The 1944-09-17 transition was at 03:00, not 01:00. This
particular change is taken from Italian law as INRiM's table,
(which says 02:00) appears to have a typo here. Also, keep the
1944-04-03 transition for Europe/Rome, as Rome was controlled by
Germany then.
The 1967-1970 and 1972-1974 fallback transitions were at 01:00,
not 00:00.
Changes to code
The code should now be buildable on AmigaOS merely by setting the
appropriate Makefile variables. (From a patch by Carsten Larsen.)
Release 2016h - 2016-10-19 23:17:57 -0700
Changes to future timestamps
Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not
2016-10-21 at 00:00. (Thanks to Sharef Mustafa.) Predict that
future fall transitions will be on the last Saturday of October
at 01:00, which is consistent with predicted spring transitions
on the last Saturday of March. (Thanks to Tim Parenti.)
Changes to past timestamps
In Turkey, transitions in 1986-1990 were at 01:00 standard time
not at 02:00, and the spring 1994 transition was on March 20, not
March 27. (Thanks to Kıvanç Yazan.)
Changes to past and future time zone abbreviations
Asia/Colombo now uses numeric time zone abbreviations like "+0530"
instead of alphabetic ones like "IST" and "LKT". Various
English-language sources use "IST", "LKT" and "SLST", with no
working consensus. (Usage of "SLST" mentioned by Sadika
Sumanapala.)
Changes to code
zic no longer mishandles relativizing file names when creating
symbolic links like /etc/localtime, when these symbolic links
are outside the usual directory hierarchy. This fixes a bug
introduced in 2016g. (Problem reported by Andreas Stieger.)
Changes to build procedure
New rules 'traditional_tarballs' and 'traditional_signatures' for
building just the traditional-format distribution. (Requested by
Deborah Goldsmith.)
The file 'version' is now put into the tzdata tarball too.
(Requested by Howard Hinnant.)
Changes to documentation and commentary
The 'Theory' file now has a section on interface stability.
(Requested by Paul Koning.) It also mentions features like
tm_zone and localtime_rz that have long been supported by the
reference code.
tz-link.htm has improved coverage of time zone boundaries suitable
for geolocation. (Thanks to heads-ups from Evan Siroky and Matt
Johnson.)
The US commentary now mentions Allen and the "day of two noons".
The Fiji commentary mentions the government's 2016-10-03 press
release. (Thanks to Raymond Kumar.)
Release 2016g - 2016-09-13 08:56:38 -0700
Changes to future timestamps
Turkey switched from EET/EEST (+02/+03) to permanent +03,
effective 2016-09-07. (Thanks to Burak AYDIN.) Use "+03" rather
than an invented abbreviation for the new time.
New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52.
(Thanks to Tim Parenti.)
Changes to past timestamps
For America/Los_Angeles, spring-forward transition times have been
corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in
1950-1966.
For zones using Soviet time on 1919-07-01, transitions to UT-based
time were at 00:00 UT, not at 02:00 local time. The affected
zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and
Europe/Ulyanovsk. (Thanks to Alexander Belopolsky.)
Changes to past and future time zone abbreviations
The Factory zone now uses the time zone abbreviation -00 instead
of a long English-language string, as -00 is now the normal way to
represent an undefined time zone.
Several zones in Antarctica and the former Soviet Union, along
with zones intended for ships at sea that cannot use POSIX TZ
strings, now use numeric time zone abbreviations instead of
invented or obsolete alphanumeric abbreviations. The affected
zones are Antarctica/Casey, Antarctica/Davis,
Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga,
Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
Europe/Minsk, Europe/Samara, Europe/Volgograd, and
Indian/Kerguelen. For Europe/Moscow the invented abbreviation MSM
was replaced by +05, whereas MSK and MSD were kept as they are not
our invention and are widely used.
Changes to zone names
Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link.
(Thanks to David Massoud.)
Changes to code
zic no longer generates binary files containing POSIX TZ-like
strings that disagree with the local time type after the last
explicit transition in the data. This fixes a bug with
Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps
on the reference platform. (Thanks to Alexander Belopolsky for
reporting the bug and suggesting a way forward.)
If the installed localtime and/or posixrules files are symbolic
links, zic now keeps them symbolic links when updating them, for
compatibility with platforms like OpenSUSE where other programs
configure these files as symlinks.
zic now avoids hard linking to symbolic links, avoids some
unnecessary mkdir and stat system calls, and uses shorter file
names internally.
zdump has a new -i option to generate transitions in a
smaller but still human-readable format. This option is
experimental, and the output format may change in future versions.
(Thanks to Jon Skeet for suggesting that an option was needed,
and thanks to Tim Parenti and Chris Rovick for further comments.)
Changes to build procedure
An experimental distribution format is available, in addition
to the traditional format which will continue to be distributed.
The new format is a tarball tzdb-VERSION.tar.lz with signature
file tzdb-VERSION.tar.lz.asc. It unpacks to a top-level directory
tzdb-VERSION containing the code and data of the traditional
two-tarball format, along with extra data that may be useful.
(Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others
for comments about the experimental format.)
The release version number is now more accurate in the usual case
where releases are built from a Git repository. For example, if
23 commits and some working-file changes have been made since
release 2016g, the version number is now something like
'2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
Tagged releases use the same version number format as before,
e.g., '2016g'. To support the more accurate version number, its
specification has moved from a line in the Makefile to a new
source file 'version'.
The experimental distribution contains a file to2050.tzs that
contains what should be the output of 'zdump -i -c 2050' on
primary zones. If this file is available, 'make check' now checks
that zdump generates this output.
'make check_web' now works on Fedora-like distributions.
Changes to documentation and commentary
tzfile.5 now documents the new restriction on POSIX TZ-like
strings that is now implemented by zic.
Comments now cite URLs for some 1917-1921 Russian DST decrees.
(Thanks to Alexander Belopolsky.)
tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J
(thanks to Meno Hochschild) and ThreeTen-Extra, and its
description of Java 8 has been brought up to date (thanks to
Stephen Colebourne). Its description of local time on Mars has
been updated to match current practice, and URLs have been updated
and some obsolete ones removed.
Release 2016f - 2016-07-05 16:26:51 +0200
Changes affecting future timestamps
The Egyptian government changed its mind on short notice, and
Africa/Cairo will not introduce DST starting 2016-07-07 after all.
(Thanks to Mina Samuel.)
Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00.
(Thanks to Stepan Golosunov.)
Changes to past and future timestamps
Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone
abbreviations instead of invented ones.
Changes affecting past timestamps
Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00.
(Thanks to Stepan Golosunov.)
Release 2016e - 2016-06-14 08:46:16 -0700
Changes affecting future timestamps
Africa/Cairo observes DST in 2016 from July 7 to the end of October.
Guess October 27 and 24:00 transitions. (Thanks to Steffen Thorsen.)
For future years, guess April's last Thursday to October's last
Thursday except for Ramadan.
Changes affecting past timestamps
Locations while uninhabited now use '-00', not 'zzz', as a
placeholder time zone abbreviation. This is inspired by Internet
RFC 3339 and is more consistent with numeric time zone
abbreviations already used elsewhere. The change affects several
arctic and antarctic locations, e.g., America/Cambridge_Bay before
1920 and Antarctica/Troll before 2005.
Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was
at 03:00, not 23:00 the previous day. (Thanks to Michael Deckers.)
Changes to code
zic now outputs a dummy transition at time 2**31 - 1 in zones
whose POSIX-style TZ strings contain a '<'. This mostly works
around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>.
(Thanks to Zhanibek Adilbekov for reporting the Qt bug.)
Changes affecting documentation and commentary
tz-link.htm says why governments should give plenty of notice for
time zone or DST changes, and refers to Matt Johnson's blog post.
tz-link.htm mentions Tzdata for Elixir. (Thanks to Matt Johnson.)
Release 2016d - 2016-04-17 22:50:29 -0700
Changes affecting future timestamps
America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30.
(Thanks to Alexander Krivenyshev for the heads-up.)
Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00.
(Thanks to Alexander Krivenyshev and Matt Johnson.)
New zone Asia/Tomsk, split off from Asia/Novosibirsk. It covers
Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29
at 02:00. (Thanks to Stepan Golosunov.)
Changes affecting past timestamps
New zone Europe/Kirov, split off from Europe/Volgograd. It covers
Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on
1989-03-26 at 02:00, roughly a year after Europe/Volgograd made
the same change. (Thanks to Stepan Golosunov.)
Russia and nearby locations had daylight-saving transitions on
1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on
1992-03-28 at 23:00 and 1992-09-26 at 23:00. (Thanks to Stepan
Golosunov.)
Many corrections to historical time in Kazakhstan from 1991
through 2005. (Thanks to Stepan Golosunov.) Replace Kazakhstan's
invented time zone abbreviations with numeric abbreviations.
Changes to commentary
Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references).
Release 2016c - 2016-03-23 00:51:27 -0700
Changes affecting future timestamps
Azerbaijan no longer observes DST. (Thanks to Steffen Thorsen.)
Chile reverts from permanent to seasonal DST. (Thanks to Juan
Correa for the heads-up, and to Tim Parenti for corrections.)
Guess that future transitions are August's and May's second
Saturdays at 24:00 mainland time. Also, call the period from
2014-09-07 through 2016-05-14 daylight saving time instead of
standard time, as that seems more appropriate now.
Changes affecting past timestamps
Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to
+02/+03 on 1989-03-26, not 1991-03-31. Europe/Volgograd changed
from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26.
(Thanks to Stepan Golosunov.)
Changes to commentary
Several updates and URLs for historical and proposed Russian changes.
(Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.)
Release 2016b - 2016-03-12 17:30:14 -0800
Compatibility note
Starting with release 2016b, some data entries cause zic implementations
derived from tz releases 2005j through 2015e to issue warnings like
"time zone abbreviation differs from POSIX standard (+03)".
These warnings should not otherwise affect zic's output and can safely be
ignored on today's platforms, as the warnings refer to a restriction in
POSIX.1-1988 that was removed in POSIX.1-2001. One way to suppress the
warnings is to upgrade to zic derived from tz releases 2015f and later.
Changes affecting future timestamps
New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and
Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on
2016-03-27 at 02:00 local time. They need distinct zones since their
post-1970 histories disagree. New zone Asia/Barnaul for Altai Krai and
Altai Republic, Russia, which will switch from +06 to +07 on the same date
and local time. The Astrakhan change is already official; the others have
passed the first reading in the State Duma and are extremely likely.
Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00.
(Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson
and Stepan Golosunov for followup.)
As a trial of a new system that needs less information to be made up,
the new zones use numeric time zone abbreviations like "+04"
instead of invented abbreviations like "ASTT".
Haiti will not observe DST in 2016. (Thanks to Jean Antoine via
Steffen Thorsen.)
Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00.
(Thanks to Hannah Kreitem.) Guess future transitions will be March's last
Saturday at 01:00, not March's last Friday at 24:00.
Changes affecting past timestamps
Europe/Chisinau observed DST during 1990, and switched from +04 to
+03 at 1990-05-06 02:00, instead of switching from +03 to +02.
(Thanks to Stepan Golosunov.)
1991 abbreviations in Europe/Samara should be SAMT/SAMST, not
KUYT/KUYST. (Thanks to Stepan Golosunov.)
Changes to code
tzselect's diagnostics and checking, and checktab.awk's checking,
have been improved. (Thanks to J William Piggott.)
tzcode now builds under MinGW. (Thanks to Ian Abbott and Esben Haabendal.)
tzselect now tests Julian-date TZ settings more accurately.
(Thanks to J William Piggott.)
Changes to commentary
Comments in zone tables have been improved. (Thanks to J William Piggott.)
tzselect again limits its menu comments so that menus fit on a
24×80 alphanumeric display.
A new web page tz-how-to.html. (Thanks to Bill Seymour.)
In the Theory file, the description of possible time zone abbreviations in
tzdata has been cleaned up, as the old description was unclear and
inconsistent. (Thanks to Alain Mouette for reporting the problem.)
Release 2016a - 2016-01-26 23:28:02 -0800
Changes affecting future timestamps
America/Cayman will not observe daylight saving this year after all.
Revert our guess that it would. (Thanks to Matt Johnson.)
Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00.
(Thanks to Alexander Krivenyshev.)
Asia/Tehran now has DST predictions for the year 2038 and later,
to be March 21 00:00 to September 21 00:00. This is likely better
than predicting no DST, albeit off by a day every now and then.
Changes affecting past and future timestamps
America/Metlakatla switched from PST all year to AKST/AKDT on
2015-11-01 at 02:00. (Thanks to Steffen Thorsen.)
America/Santa_Isabel has been removed, and replaced with a
backward compatibility link to America/Tijuana. Its contents were
apparently based on a misreading of Mexican legislation.
Changes affecting past timestamps
Asia/Karachi's two transition times in 2002 were off by a minute.
(Thanks to Matt Johnson.)
Changes affecting build procedure
An installer can now combine leap seconds with use of the backzone file,
e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'.
The old 'make posix_packrat' rule is now marked as obsolescent.
(Thanks to Ian Abbott for an initial implementation.)
Changes affecting documentation and commentary
A new file LICENSE makes it easier to see that the code and data
are mostly public-domain. (Thanks to James Knight.) The three
non-public-domain files now use the current (3-clause) BSD license
instead of older versions of that license.
tz-link.htm mentions the BDE library (thanks to Andrew Paprocki),
CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section
on editing tz source files (with a mention of Sublime zoneinfo,
thanks to Gilmore Davidson).
The Theory and asia files now mention the 2015 book "The Global
Transformation of Time, 1870-1950", and cite a couple of reviews.
The America/Chicago entry now documents the informal use of US
central time in Fort Pierre, South Dakota. (Thanks to Rick
McDermid, Matt Johnson, and Steve Jones.)
Release 2015g - 2015-10-01 00:39:51 -0700
Changes affecting future timestamps
Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25.
(Thanks to Fatih.)
Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time.
(Thanks to Alexander Krivenyshev.)
Fiji's 2016 fall-back transition is scheduled for January 17, not 24.
(Thanks to Ken Rylander.)
Fort Nelson, British Columbia will not fall back on 2015-11-01. It has
effectively been on MST (-0700) since it advanced its clocks on 2015-03-08.
New zone America/Fort_Nelson. (Thanks to Matt Johnson.)
Changes affecting past timestamps
Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00.
Changes affecting code
localtime no longer mishandles America/Anchorage after 2037.
(Thanks to Bradley White for reporting the bug.)
On hosts with signed 32-bit time_t, localtime no longer mishandles
Pacific/Fiji after 2038-01-16 14:00 UTC.
The localtime module allows the variables 'timezone', 'daylight',
and 'altzone' to be in common storage shared with other modules,
and declares them in case the system <time.h> does not.
(Problems reported by Kees Dekker.)
On platforms with tm_zone, strftime.c now assumes it is not NULL.
This simplifies the code and is consistent with zdump.c.
(Problem reported by Christos Zoulas.)
Changes affecting documentation
The tzfile man page now documents that transition times denote the
starts (not the ends) of the corresponding time periods.
(Ambiguity reported by Bill Seymour.)
Release 2015f - 2015-08-10 18:06:56 -0700
Changes affecting future timestamps
North Korea switches to +0830 on 2015-08-15. (Thanks to Steffen Thorsen.)
The abbreviation remains "KST". (Thanks to Robert Elz.)
Uruguay no longer observes DST. (Thanks to Steffen Thorsen
and Pablo Camargo.)
Changes affecting past and future timestamps
Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
(Thanks to Roman Tudos.)
Changes affecting data format and code
zic's '-y YEARISTYPE' option is no longer documented. The TYPE
field of a Rule line should now be '-'; the old values 'even',
'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented.
Although the implementation has not changed, these features do not
work in the default installation, they are not used in the data,
and they are now considered obsolescent.
zic now checks that two rules don't take effect at the same time.
(Thanks to Jon Skeet and Arthur David Olson.) Constraints on
simultaneity are now documented.
The two characters '%z' in a zone format now stand for the UT
offset, e.g., '-07' for seven hours behind UT and '+0530' for
five hours and thirty minutes ahead. This better supports time
zone abbreviations conforming to POSIX.1-2001 and later.
Changes affecting installed data files
Comments for America/Halifax and America/Glace_Bay have been improved.
(Thanks to Brian Inglis.)
Data entries have been simplified for Atlantic/Canary, Europe/Simferopol,
Europe/Sofia, and Europe/Tallinn. This yields slightly smaller
installed data files for Europe/Simferopol and Europe/Tallinn.
It does not affect timestamps. (Thanks to Howard Hinnant.)
Changes affecting code
zdump and zic no longer warn about valid time zone abbreviations
like '-05'.
Some Visual Studio 2013 warnings have been suppressed.
(Thanks to Kees Dekker.)
'date' no longer sets the time of day and its -a, -d, -n and -t
options have been removed. Long obsolescent, the implementation
of these features had porting problems. Builders no longer need
to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H.
(Thanks to Kees Dekker for pointing out the problem.)
Changes affecting documentation
The Theory file mentions naming issues earlier, as these seem to be
poorly publicized (thanks to Gilmore Davidson for reporting the problem).
tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant).
Mention that Herbert Samuel introduced the term "Summer Time".
Release 2015e - 2015-06-13 10:56:02 -0700
Changes affecting future timestamps
Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00,
not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.)
Assume Cayman Islands will observe DST starting next year, using US rules.
Although it isn't guaranteed, it is the most likely.
Changes affecting data format
The file 'iso3166.tab' now uses UTF-8, so that its entries can better
spell the names of Åland Islands, Côte d'Ivoire, and Réunion.
Changes affecting code
When displaying data, tzselect converts it to the current locale's
encoding if the iconv command works. (Problem reported by random832.)
tzselect no longer mishandles Dominica, fixing a bug introduced
in Release 2014f. (Problem reported by Owen Leibman.)
zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\".
This fixes a bug introduced in Release 2014f.
(Problem reported by Leonardo Chiquitto.)
Release 2015d - 2015-04-24 08:09:46 -0700
Changes affecting future timestamps
Egypt will not observe DST in 2015 and will consider canceling it
permanently. For now, assume no DST indefinitely.
(Thanks to Ahmed Nazmy and Tim Parenti.)
Changes affecting past timestamps
America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not
1966-07-01. Also, Yukon's time zone history is documented better.
(Thanks to Brian Inglis and Dennis Ferguson.)
Change affecting past and future time zone abbreviations
The abbreviations for Hawaii-Aleutian standard and daylight times
have been changed from HAST/HADT to HST/HDT, as per US Government
Printing Office style. This affects only America/Adak since 1983,
as America/Honolulu was already using the new style.
Changes affecting code
zic has some minor performance improvements.
Release 2015c - 2015-04-11 08:55:55 -0700
Changes affecting future timestamps
Egypt's spring-forward transition is at 24:00 on April's last Thursday,
not 00:00 on April's last Friday. 2015's transition will therefore be on
Thursday, April 30 at 24:00, not Friday, April 24 at 00:00. Similar fixes
apply to 2026, 2037, 2043, etc. (Thanks to Steffen Thorsen.)
Changes affecting past timestamps
The following changes affect some pre-1991 Chile-related timestamps
in America/Santiago, Antarctica/Palmer, and Pacific/Easter.
The 1910 transition was January 10, not January 1.
The 1918 transition was September 10, not September 1.
The UT -04 time observed from 1932 to 1942 is now considered to
be standard time, not year-round DST.
Santiago observed DST (UT -03) from 1946-07-15 through
1946-08-31, then reverted to standard time, then switched to -05
on 1947-04-01.
Assume transitions before 1968 were at 00:00, since we have no data
saying otherwise.
The spring 1988 transition was 1988-10-09, not 1988-10-02.
The fall 1990 transition was 1990-03-11, not 1990-03-18.
Assume no UT offset change for Pacific/Easter on 1890-01-01,
and omit all transitions on Pacific/Easter from 1942 through 1946
since we have no data suggesting that they existed.
One more zone has been turned into a link, as it differed
from an existing zone only for older timestamps. As usual,
this change affects UT offsets in pre-1970 timestamps only.
The zone's old contents have been moved to the 'backzone' file.
The affected zone is America/Montreal.
Changes affecting commentary
Mention the TZUpdater tool.
Mention "The Time Now". (Thanks to Brandon Ramsey.)
Release 2015b - 2015-03-19 23:28:11 -0700
Changes affecting future timestamps
Mongolia will start observing DST again this year, from the last
Saturday in March at 02:00 to the last Saturday in September at 00:00.
(Thanks to Ganbold Tsagaankhuu.)
Palestine will start DST on March 28, not March 27. Also,
correct the fall 2014 transition from September 26 to October 24.
Adjust future predictions accordingly. (Thanks to Steffen Thorsen.)
Changes affecting past timestamps
The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a
regression. (Thanks to Stuart Bishop for reporting the problem.)
Some more zones have been turned into links, when they differed
from existing zones only for older timestamps. As usual,
these changes affect UT offsets in pre-1970 timestamps only.
Their old contents have been moved to the 'backzone' file.
The affected zones are: America/Antigua, America/Cayman,
Pacific/Midway, and Pacific/Saipan.
Changes affecting time zone abbreviations
Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD".
(Thanks to Hank W.)
Changes affecting code
Fix integer overflow bug in reference 'mktime' implementation.
(Problem reported by Jörg Richter.)
Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries
to be used in the same executable as standard-library time_t functions.
(Problems reported by Bradley White.)
Changes affecting commentary
Cite the recent Mexican decree changing Quintana Roo's time zone.
(Thanks to Carlos Raúl Perasso.)
Likewise for the recent Chilean decree. (Thanks to Eduardo Romero Urra.)
Update info about Mars time.
Release 2015a - 2015-01-29 22:35:20 -0800
Changes affecting future timestamps
The Mexican state of Quintana Roo, represented by America/Cancun,
will shift from Central Time with DST to Eastern Time without DST
on 2015-02-01 at 02:00. (Thanks to Steffen Thorsen and Gwillim Law.)
Chile will not change clocks in April or thereafter; its new standard time
will be its old daylight saving time. This affects America/Santiago,
Pacific/Easter, and Antarctica/Palmer. (Thanks to Juan Correa.)
New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.
(Thanks to Tim Parenti.)
Changes affecting past timestamps
Iceland observed DST in 1919 and 1921, and its 1939 fallback
transition was Oct. 29, not Nov. 29. Remove incorrect data from
Shanks about time in Iceland between 1837 and 1908.
Some more zones have been turned into links, when they differed
from existing zones only for older timestamps. As usual,
these changes affect UT offsets in pre-1970 timestamps only.
Their old contents have been moved to the 'backzone' file.
The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait,
and Asia/Muscat.
Changes affecting code
tzalloc now scrubs time zone abbreviations compatibly with the way
that tzset always has, by replacing invalid bytes with '_' and by
shortening too-long abbreviations.
tzselect ports to POSIX awk implementations, no longer mishandles
POSIX TZ settings when GNU awk is used, and reports POSIX TZ
settings to the user. (Thanks to Stefan Kuhn.)
Changes affecting build procedure
'make check' now checks for links to links in the data.
One such link (for Africa/Asmera) has been fixed.
(Thanks to Stephen Colebourne for pointing out the problem.)
Changes affecting commentary
The leapseconds file commentary now mentions the expiration date.
(Problem reported by Martin Burnicki.)
Update Mexican Library of Congress URL.
Release 2014j - 2014-11-10 17:37:11 -0800
Changes affecting current and future timestamps
Turks & Caicos' switch from US eastern time to UT -04 year-round
did not occur on 2014-11-02 at 02:00. It's currently scheduled
for 2015-11-01 at 02:00. (Thanks to Chris Walton.)
Changes affecting past timestamps
Many pre-1989 timestamps have been corrected for Asia/Seoul and
Asia/Pyongyang, based on sources for the Korean-language Wikipedia
entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no
longer guess that Pyongyang mimicked Seoul time after World War II,
as this is politically implausible.
Some more zones have been turned into links, when they differed
from existing zones only for older timestamps. As usual,
these changes affect UT offsets in pre-1970 timestamps only.
Their old contents have been moved to the 'backzone' file.
The affected zones are: Africa/Addis_Ababa, Africa/Asmara,
Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala,
Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and
Indian/Mayotte.
Changes affecting commentary
The commentary is less enthusiastic about Shanks as a source,
and is more careful to distinguish UT from UTC.
Release 2014i - 2014-10-21 22:04:57 -0700
Changes affecting future timestamps
Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00.
(Thanks to Ken Rylander for the heads-up.) Guess that future
years will use a similar pattern.
A new Zone Pacific/Bougainville, for the part of Papua New Guinea
that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00.
(Thanks to Kiley Walbom for the heads-up.)
Changes affecting time zone abbreviations
Since Belarus is not changing its clocks even though Moscow is,
the time zone abbreviation in Europe/Minsk is changing from FET
to its more traditional value MSK on 2014-10-26 at 01:00.
(Thanks to Alexander Bokovoy for the heads-up about Belarus.)
The new abbreviation IDT stands for the pre-1976 use of UT +08 in
Indochina, to distinguish it better from ICT (+07).
Changes affecting past timestamps
Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976
(thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's
authoritative book). Asia/Ho_Chi_Minh has been added to
zone1970.tab, to give tzselect users in Vietnam two choices,
since north and south Vietnam disagreed after our 1970 cutoff.
Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as
they differed from existing zones only for older timestamps. As
usual, these changes affect pre-1970 timestamps only. Their old
contents have been moved to the 'backzone' file.
Changes affecting code
The time-related library functions now set errno on failure, and
some crashes in the new tzalloc-related library functions have
been fixed. (Thanks to Christos Zoulas for reporting most of
these problems and for suggesting fixes.)
If USG_COMPAT is defined and the requested timestamp is standard time,
the tz library's localtime and mktime functions now set the extern
variable timezone to a value appropriate for that timestamp; and
similarly for ALTZONE, daylight saving time, and the altzone variable.
This change is a companion to the tzname change in 2014h, and is
designed to make timezone and altzone more compatible with tzname.
The tz library's functions now set errno to EOVERFLOW if they fail
because the result cannot be represented. ctime and ctime_r now
return NULL and set errno when a timestamp is out of range, rather
than having undefined behavior.
Some bugs associated with the new 2014g functions have been fixed.
This includes a bug that largely incapacitated the new functions
time2posix_z and posix2time_z. (Thanks to Christos Zoulas.)
It also includes some uses of uninitialized variables after tzalloc.
The new code uses the standard type 'ssize_t', which the Makefile
now gives porting advice about.
Changes affecting commentary
Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis).
Release 2014h - 2014-09-25 18:59:03 -0700
Changes affecting past timestamps
America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28.
Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01,
not 1920-01-06. The old entry was based on a misinterpretation of Shanks.
Some more zones have been turned into links, when they differed
from existing zones only for older timestamps. As usual,
these changes affect UT offsets in pre-1970 timestamps only.
Their old contents have been moved to the 'backzone' file.
The affected zones are: Africa/Blantyre, Africa/Bujumbura,
Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi,
Africa/Lusaka, Africa/Maseru, and Africa/Mbabane.
Changes affecting code
zdump -V and -v now output gmtoff= values on all platforms,
not merely on platforms defining TM_GMTOFF.
The tz library's localtime and mktime functions now set tzname to a value
appropriate for the requested timestamp, and zdump now uses this
on platforms not defining TM_ZONE, fixing a 2014g regression.
(Thanks to Tim Parenti for reporting the problem.)
The tz library no longer sets tzname if localtime or mktime fails.
zdump -c no longer mishandles transitions near year boundaries.
(Thanks to Tim Parenti for reporting the problem.)
An access to uninitialized data has been fixed.
(Thanks to Jörg Richter for reporting the problem.)
When THREAD_SAFE is defined, the code ports to the C11 memory model.
A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined
and two threads race to initialize data used by gmtime-like functions.
(Thanks to Andy Heninger for reporting the problems.)
Changes affecting build procedure
'make check' now checks better for properly sorted data.
Changes affecting documentation and commentary
zdump's gmtoff=N output is now documented, and its isdst=D output
is now documented to possibly output D values other than 0 or 1.
zdump -c's treatment of years is now documented to use the
Gregorian calendar and Universal Time without leap seconds,
and its behavior at cutoff boundaries is now documented better.
(Thanks to Arthur David Olson and Tim Parenti for reporting the problems.)
Programs are now documented to use the proleptic Gregorian calendar.
(Thanks to Alan Barrett for the suggestion.)
Fractional-second GMT offsets have been documented for civil time
in 19th-century Chennai, Jakarta, and New York.
Release 2014g - 2014-08-28 12:31:23 -0700
Changes affecting future timestamps
Turks & Caicos is switching from US eastern time to UT -04
year-round, modeled as a switch on 2014-11-02 at 02:00.
[As noted in 2014j, this switch was later delayed.]
Changes affecting past timestamps
Time in Russia or the USSR before 1926 or so has been corrected by
a few seconds in the following zones: Asia/Irkutsk,
Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi,
Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara. For
Asia/Yekaterinburg the correction is a few minutes. (Thanks to
Vladimir Karpinsky.)
The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
Atlantic/Azores, and Atlantic/Madeira. Also, Lisbon's pre-1912
GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32.
(Thanks to Stephen Colebourne for pointing to the decree.)
Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59.
A new file 'backzone' contains data which may appeal to
connoisseurs of old timestamps, although it is out of scope for
the tz database, is often poorly sourced, and contains some data
that is known to be incorrect. The new file is not recommended
for ordinary use and its entries are not installed by default.
(Thanks to Lester Caine for the high-quality Jersey, Guernsey, and
Isle of Man entries.)
Some more zones have been turned into links, when they differed
from existing zones only for older timestamps. As usual,
these changes affect UT offsets in pre-1970 timestamps only.
Their old contents have been moved to the 'backzone' file.
The affected zones are: Africa/Bangui, Africa/Brazzaville,
Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda,
Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo.
Changes affecting code
Unless NETBSD_INSPIRED is defined to 0, the tz library now
supplies functions for creating and using objects that represent
timezones. The new functions are tzalloc, tzfree, localtime_rz,
mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and
time2posix_z. They are intended for performance: for example,
localtime_rz (unlike localtime_r) is trivially thread-safe without
locking. (Thanks to Christos Zoulas for proposing NetBSD-inspired
functions, and to Alan Barrett and Jonathan Lennox for helping to
debug the change.)
zdump now builds with the tz library unless USE_LTZ is defined to 0,
This lets zdump use tz features even if the system library lacks them.
To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.
zdump now uses localtime_rz if available, as it's significantly faster,
and it can help zdump better diagnose invalid timezone names.
Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_RZ
defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is
not available, zdump now uses localtime_r and tzset if available,
as this is a bit cleaner and faster than plain localtime. Compile
with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
lacks these two functions.
If THREAD_SAFE is defined to 1, the tz library is now thread-safe.
Although not needed for tz's own applications, which are single-threaded,
this supports POSIX better if the tz library is used in multithreaded apps.
Some crashes have been fixed when zdump or the tz library is given
invalid or outlandish input.
The tz library no longer mishandles leap seconds on platforms with
unsigned time_t in timezones that lack ordinary transitions after 1970.
The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not
already defined, to make it easier to configure on common platforms.
Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this.
Unless the new macro UNINIT_TRAP is defined to 1, the tz code now
assumes that reading uninitialized memory yields garbage values
but does not cause other problems such as traps.
If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
more likely to guess right for ambiguous timestamps near
transitions where tm_isdst does not change.
If HAVE_STRFTIME_L is defined to 1, the tz library now defines
strftime_l for compatibility with recent versions of POSIX.
Only the C locale is supported, though. HAVE_STRFTIME_L defaults
to 1 on recent POSIX versions, and to 0 otherwise.
tzselect -c now uses a hybrid distance measure that works better
in Africa. (Thanks to Alan Barrett for noting the problem.)
The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used,
or when time_tz is defined.
When HAVE_UTMPX_H is set the 'date' command now builds on systems
whose <utmpx.h> file does not define WTMPX_FILE, and when setting
the date it updates the wtmpx file if _PATH_WTMPX is defined.
This affects GNU/Linux and similar systems.
For easier maintenance later, some C code has been simplified,
some lint has been removed, and the code has been tweaked so that
plain 'make' is more likely to work.
The C type 'bool' is now used for boolean values, instead of 'int'.
The long-obsolete LOCALE_HOME code has been removed.
The long-obsolete 'gtime' function has been removed.
Changes affecting build procedure
'zdump' no longer links in ialloc.o, as it's not needed.
'make check_time_t_alternatives' no longer assumes GNU diff.
Changes affecting distribution tarballs
The files checktab.awk and zoneinfo2tdf.pl are now distributed in
the tzdata tarball instead of the tzcode tarball, since they help
maintain the data. The NEWS and Theory files are now also
distributed in the tzdata tarball, as they're relevant for data.
(Thanks to Alan Barrett for pointing this out.) Also, the
leapseconds.awk file is no longer distributed in the tzcode
tarball, since it belongs in the tzdata tarball (where 2014f
inadvertently also distributed it).
Changes affecting documentation and commentary
A new file CONTRIBUTING is distributed. (Thanks to Tim Parenti for
suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms
for debugging it.)
The man pages have been updated to use function prototypes,
to document thread-safe variants like localtime_r, and to document
the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and
mktime_z.
The fields in Link lines have been renamed to be more descriptive
and more like the parameters of 'ln'. LINK-FROM has become TARGET,
and LINK-TO has become LINK-NAME.
tz-link.htm mentions the IETF's tzdist working group; Windows
Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab.
Some broken URLs have been fixed in the commentary. (Thanks to
Lester Caine.)
Commentary about Philippines DST has been updated, and commentary
on pre-1970 time in India has been added.
Release 2014f - 2014-08-05 17:42:36 -0700
Changes affecting future timestamps
Russia will subtract an hour from most of its time zones on 2014-10-26
at 02:00 local time. (Thanks to Alexander Krivenyshev.)
There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky
Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug
(Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast
(Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic
(Europe/Samara) are not changing their clocks. The changed zones are
Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd,
Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk,
Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga,
Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours
subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected,
but not its UTC offset. Two zones are added: Asia/Chita (split
from Asia/Yakutsk, and also with two hours subtracted) and
Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour
subtracted). (Thanks to Tim Parenti for much of the above.)
Changes affecting time zone abbreviations
Australian eastern time zone abbreviations are now AEST/AEDT not EST,
and similarly for the other Australian zones. That is, for eastern
standard and daylight saving time the abbreviations are AEST and AEDT
instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT,
and AWST/AWDT are now used instead of the former CST, CWST, and WST.
This change does not affect UT offsets, only time zone abbreviations.
(Thanks to Rich Tibbett and many others.)
Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07)
effective 2014-10-26 at 02:00 local time.
The time zone abbreviation for Xinjiang Time (observed in Ürümqi)
has been changed from URUT to XJT. (Thanks to Luther Ma.)
Prefer MSK/MSD for Moscow time in Russia, even in other cities.
Similarly, prefer EET/EEST for eastern European time in Russia.
Change time zone abbreviations in (western) Samoa to use "ST" and
"DT" suffixes, as this is more likely to match common practice.
Prefix "W" to (western) Samoa time when its standard-time offset
disagrees with that of American Samoa.
America/Metlakatla now uses PST, not MeST, to abbreviate its time zone.
Time zone abbreviations have been updated for Japan's two time
zones used 1896-1937. JWST now stands for Western Standard
Time, and JCST for Central Standard Time (formerly this was CJT).
These abbreviations are now used for time in Korea, Taiwan,
and Sakhalin while controlled by Japan.
Changes affecting past timestamps
China's five zones have been simplified to two, since the post-1970
differences in the other three seem to have been imaginary. The
zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been
removed; backwards-compatibility links still work, albeit with
different behaviors for timestamps before May 1980. Asia/Urumqi's
1980 transition to UT +08 has been removed, so that it is now at
+06 and not +08. (Thanks to Luther Ma and to Alois Treindl;
Treindl sent helpful translations of two papers by Guo Qingsheng.)
Some zones have been turned into links, when they differed from existing
zones only for older UT offsets where data entries were likely invented.
These changes affect UT offsets in pre-1970 timestamps only. This is
similar to the change in release 2013e, except this time for western
Africa. The affected zones are: Africa/Bamako, Africa/Banjul,
Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome,
Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and
Atlantic/St_Helena. This also affects the backwards-compatibility
link Africa/Timbuktu. (Thanks to Alan Barrett, Stephen Colebourne,
Tim Parenti, and David Patte for reporting problems in earlier
versions of this change.)
Asia/Shanghai's pre-standard-time UT offset has been changed from
8:05:57 to 8:05:43, the location of Xujiahui Observatory. Its
transition to standard time has been changed from 1928 to 1901.
Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01,
then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945.
In 1946 it observed DST from 05-15 through 09-30; in 1947
from 04-15 through 10-31; and in 1979 from 07-01 through 09-30.
(Thanks to Yu-Cheng Chuang.)
Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950.
Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not
10-03 at 00:00. (Thanks to Konstantin Hyppönen.)
Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the
period from 1911 to 1950.
Pacific/Chatham has been changed to New Zealand standard time plus
45 minutes for the period before 1957, reflecting a 1956 remark in
the New Zealand parliament.
Europe/Budapest has several pre-1946 corrections: in 1918 the transition
out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in
1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08
not 04-06 at 02:00; and there was no DST in 1920.
Africa/Accra is now assumed to have observed DST from 1920 through 1935.
Time in Russia before 1927 or so has been corrected by a few seconds in
the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi,
Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and
Europe/Riga. Also, Moscow's location has been changed to its Kilometer 0
point. (Thanks to Vladimir Karpinsky for the Moscow changes.)
Changes affecting data format
A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data.
The new file's extended format allows multiple country codes per zone.
The older file is still installed but is deprecated; its format is
not changing and it will still be distributed for a while, but new
applications should use the new file.
The new file format simplifies maintenance of obscure locations.
To test this, it adds coverage for the Crozet Islands and the
Scattered Islands. (Thanks to Tobias Conradi and Antoine Leca.)
The file 'iso3166.tab' is planned to switch from ASCII to UTF-8.
It is still ASCII now, but commentary about the switch has been added.
The new file 'zone1970.tab' already uses UTF-8.
Changes affecting code
'localtime', 'mktime', etc. now use much less stack space if ALL_STATE
is defined. (Thanks to Elliott Hughes for reporting the problem.)
'zic' no longer mishandles input when ignoring case in locales that
are not compatible with English, e.g., unibyte Turkish locales when
compiled with HAVE_GETTEXT.
Error diagnostics of 'zic' and 'yearistype' have been reworded so that
they no longer use ASCII '-' as if it were a dash.
'zic' now rejects output file names that contain '.' or '..' components.
(Thanks to Tim Parenti for reporting the problem.)
'zic -v' now warns about output file names that do not follow
POSIX rules, or that contain a digit or '.'. (Thanks to Arthur
David Olson for starting the ball rolling on this.)
Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0.
Changes affecting build procedure
'zic' no longer links in localtime.o and asctime.o, as they're not needed.
(Thanks to John Cochran.)
Changes affecting documentation and commentary
The 'Theory' file documents legacy names, the longstanding
exceptions to the POSIX-inspired file name rules.
The 'zic' documentation clarifies the role of time types when
interpreting dates. (Thanks to Arthur David Olson.)
Documentation and commentary now prefer UTF-8 to US-ASCII,
allowing the use of proper accents in foreign words and names.
Code and data have not changed because of this. (Thanks to
Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug
this.)
Non-HTML documentation and commentary now use plain-text URLs instead of
HTML insertions, and are more consistent about bracketing URLs when they
are not already surrounded by white space. (Thanks to suggestions by
Steffen Nurpmeso.)
There is new commentary about Xujiahui Observatory, the five time-zone
project in China from 1918 to 1949, timekeeping in Japanese-occupied
Shanghai, and Tibet Time in the 1950s. The sharp-eyed can spot the
warlord Jin Shuren in the data.
Commentary about the coverage of each Russian zone has been standardized.
(Thanks to Tim Parenti.)
There is new commentary about contemporary timekeeping in Ethiopia.
Obsolete comments about a 2007 proposal for DST in Kuwait has been removed.
There is new commentary about time in Poland in 1919.
Proper credit has been given to DST inventor George Vernon Hudson.
Commentary about time in Metlakatla, AK and Resolute, NU has been
improved, with a new source for the former.
In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it
is uninhabited.
Commentary about permanent Antarctic bases has been updated.
Several typos have been corrected. (Thanks to Tim Parenti for
contributing some of these fixes.)
tz-link.htm now mentions the JavaScript libraries Moment Timezone,
TimezoneJS.Date, Walltime-js, and Timezone. (Thanks to a heads-up
from Matt Johnson.) Also, it mentions the Go 'latlong' package.
(Thanks to a heads-up from Dirkjan Ochtman.)
The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998
have been removed. These obsolescent US Naval Observatory entries were no
longer helpful for maintenance. (Thanks to Tim Parenti for the suggestion.)
Release 2014e - 2014-06-12 21:53:52 -0700
Changes affecting near-future timestamps
Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00.
(Thanks to Imed Chihi.) Guess that from 2015 on Egypt will temporarily
switch to standard time at 24:00 the last Thursday before Ramadan, and
back to DST at 00:00 the first Friday after Ramadan.
Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00. (Thanks
to Milamber Space Network.) Guess that from 2015 on Morocco will
temporarily switch to standard time at 03:00 the last Saturday before
Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.
Changes affecting past timestamps
The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of
"MSD" for Moscow's double daylight time in summer 1921. Also, a typo
"VLASST" has been repaired to be "VLAST" for Vladivostok summer time
in 1991. (Thanks to Hank W. for reporting the problems.)
Changes affecting commentary
tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the
draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and
removes stale pointers to World Time Explorer and WORLDTIME.
Release 2014d - 2014-05-27 21:34:40 -0700
Changes affecting code
zic no longer generates files containing timestamps before the Big Bang.
This works around GNOME glib bug 878
<https://gitlab.gnome.org/GNOME/glib/issues/878>
(Thanks to Leonardo Chiquitto for reporting the bug, and to
Arthur David Olson and James Cloos for suggesting improvements to the fix.)
Changes affecting documentation
tz-link.htm now mentions GNOME.
Release 2014c - 2014-05-13 07:44:13 -0700
Changes affecting near-future timestamps
Egypt observes DST starting 2014-05-15 at 24:00.
(Thanks to Ahmad El-Dardiry and Gunther Vermier.)
Details have not been announced, except that DST will not be observed
during Ramadan. Guess that DST will stop during the same Ramadan dates as
Morocco, and that Egypt's future spring and fall transitions will be the
same as 2010 when it last observed DST, namely April's last Friday at
00:00 to September's last Thursday at 23:00 standard time. Also, guess
that Ramadan transitions will be at 00:00 standard time.
Changes affecting code
zic now generates transitions for minimum time values, eliminating guesswork
when handling low-valued timestamps. (Thanks to Arthur David Olson.)
Port to Cygwin sans glibc. (Thanks to Arthur David Olson.)
Changes affecting commentary and documentation
Remove now-confusing comment about Jordan. (Thanks to Oleksii Nochovnyi.)
Release 2014b - 2014-03-24 21:28:50 -0700
Changes affecting near-future timestamps
Crimea switches to Moscow time on 2014-03-30 at 02:00 local time.
(Thanks to Alexander Krivenyshev.) Move its zone.tab entry from UA to RU.
New entry for Troll station, Antarctica. (Thanks to Paul-Inge Flakstad and
Bengt-Inge Larsson.) This is currently an approximation; a better version
will require the zic and localtime fixes mentioned below, and the plan is
to wait for a while until at least the zic fixes propagate.
Changes affecting code
'zic' and 'localtime' no longer reject locations needing four transitions
per year for the foreseeable future. (Thanks to Andrew Main (Zefram).)
Also, 'zic' avoids some unlikely failures due to integer overflow.
Changes affecting build procedure
'make check' now detects Rule lines defined but never used.
The NZAQ rules, an instance of this problem, have been removed.
Changes affecting commentary and documentation
Fix Tuesday/Thursday typo in description of time in Israel.
(Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.)
Microsoft Windows 8.1 doesn't support tz database names. (Thanks
to Donald MacQueen.) Instead, the Microsoft Windows Store app
library supports them.
Add comments about Johnston Island time in the 1960s.
(Thanks to Lyle McElhaney.)
Morocco's 2014 DST start will be as predicted.
(Thanks to Sebastien Willemijns.)
Release 2014a - 2014-03-07 23:30:29 -0800
Changes affecting near-future timestamps
Turkey begins DST on 2014-03-31, not 03-30. (Thanks to Faruk Pasin for
the heads-up, and to Tim Parenti for simplifying the update.)
Changes affecting past timestamps
Fiji ended DST on 2014-01-19 at 02:00, not the previously scheduled 03:00.
(Thanks to Steffen Thorsen.)
Ukraine switched from Moscow to Eastern European time on 1990-07-01
(not 1992-01-01), and observed DST during the entire next winter.
(Thanks to Vladimir in Moscow via Alois Treindl.)
In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03.
(Thanks to Avigdor Finkelstein.)
Changes affecting code
A uninitialized-storage bug in 'localtime' has been fixed.
(Thanks to Logan Chien.)
Changes affecting the build procedure
The settings for 'make check_web' now default to Ubuntu 13.10.
Changes affecting commentary and documentation
The boundary of the US Pacific time zone is given more accurately.
(Thanks to Alan Mintz.)
Chile's 2014 DST will be as predicted. (Thanks to José Miguel Garrido.)
Paraguay's 2014 DST will be as predicted. (Thanks to Carlos Raúl Perasso.)
Better descriptions of countries with same time zone history as
Trinidad and Tobago since 1970. (Thanks to Alan Barrett for suggestion.)
Several changes affect tz-link.htm, the main web page.
Mention Time.is (thanks to Even Scharning) and WX-now (thanks to
David Braverman).
Mention xCal (Internet RFC 6321) and jCal.
Microsoft has some support for tz database names.
CLDR data formats include both XML and JSON.
Mention Maggiolo's map of solar vs standard time.
(Thanks to Arthur David Olson.)
Mention TZ4Net. (Thanks to Matt Johnson.)
Mention the timezone-olson Haskell package.
Mention zeitverschiebung.net. (Thanks to Martin Jäger.)
Remove moribund links to daylight-savings-time.info and to
Simple Timer + Clocks.
Update two links. (Thanks to Oscar van Vlijmen.)
Fix some formatting glitches, e.g., remove random newlines from
abbr elements' title attributes.
Release 2013i - 2013-12-17 07:25:23 -0800
Changes affecting near-future timestamps:
Jordan switches back to standard time at 00:00 on December 20, 2013.
The 2006-2011 transition schedule is planned to resume in 2014.
(Thanks to Steffen Thorsen.)
Changes affecting past timestamps:
In 2004, Cuba began DST on March 28, not April 4.
(Thanks to Steffen Thorsen.)
Changes affecting code
The compile-time flag NOSOLAR has been removed, as nowadays the
benefit of slightly shrinking runtime table size is outweighed by the
cost of disallowing potential future updates that exceed old limits.
Changes affecting documentation and commentary
The files solar87, solar88, and solar89 are no longer distributed.
They were a negative experiment - that is, a demonstration that
tz data can represent solar time only with some difficulty and error.
Their presence in the distribution caused confusion, as Riyadh
civil time was generally not solar time in those years.
tz-link.htm now mentions Noda Time. (Thanks to Matt Johnson.)
Release 2013h - 2013-10-25 15:32:32 -0700
Changes affecting current and future timestamps:
Libya has switched its UT offset back to +02 without DST, instead
of +01 with DST. (Thanks to Even Scharning.)
Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules.
(Thanks to Gwillim Law.)
Changes affecting future timestamps:
Acre and (we guess) western Amazonas will switch from UT -04 to -05
on 2013-11-10. This affects America/Rio_Branco and America/Eirunepe.
(Thanks to Steffen Thorsen.)
Add entries for DST transitions in Morocco in the year 2038.
This avoids some year-2038 glitches introduced in 2013g.
(Thanks to Yoshito Umaoka for reporting the problem.)
Changes affecting API
The 'tzselect' command no longer requires the 'select' command,
and should now work with /bin/sh on more platforms. It also works
around a bug in BusyBox awk before version 1.21.0. (Thanks to
Patrick 'P. J.' McDermott and Alan Barrett.)
Changes affecting code
Fix localtime overflow bugs with 32-bit unsigned time_t.
zdump no longer assumes sscanf returns maximal values on overflow.
Changes affecting the build procedure
The builder can specify which programs to use, if any, instead of
'ar' and 'ranlib', and libtz.a is now built locally before being
installed. (Thanks to Michael Forney.)
A dependency typo in the 'zdump' rule has been fixed.
(Thanks to Andrew Paprocki.)
The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f'
work as specified by POSIX.2-1992 or later; this is portable nowadays.
'make clean' no longer removes 'leapseconds', since it's
host-independent and is part of the distribution.
The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed.
Changes affecting documentation and commentary
tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol
(thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle).
Update URLs in tz-link page. Add URLs for Microsoft Windows, since
8.1 introduces tz support. Remove URLs for Tru64 and UnixWare (no
longer maintained) and for old advisories. SOFA now does C.
Release 2013g - 2013-09-30 21:08:26 -0700
Changes affecting current and near-future timestamps
Morocco now observes DST from the last Sunday in March to the last
Sunday in October, not April to September respectively. (Thanks
to Steffen Thorsen.)
Changes affecting 'zic'
'zic' now runs on platforms that lack both hard links and symlinks.
(Thanks to Theo Veenker for reporting the problem, for MinGW.)
Also, fix some bugs on platforms that lack hard links but have symlinks.
'zic -v' again warns that Asia/Tehran has no POSIX environment variable
to predict the far future, fixing a bug introduced in 2013e.
Changes affecting the build procedure
The 'leapseconds' file is again put into the tzdata tarball.
Also, 'leapseconds.awk', so tzdata is self-contained. (Thanks to
Matt Burgess and Ian Abbott.) The timestamps of these and other
dependent files in tarballs are adjusted more consistently.
Changes affecting documentation and commentary
The README file is now part of the data tarball as well as the code.
It now states that files are public domain unless otherwise specified.
(Thanks to Andrew Main (Zefram) for asking for clarifications.)
Its details about the 1989 release moved to a place of honor near
the end of NEWS.
Release 2013f - 2013-09-24 23:37:36 -0700
Changes affecting near-future timestamps
Tocantins will very likely not observe DST starting this spring.
(Thanks to Steffen Thorsen.)
Jordan will likely stay at UT +03 indefinitely, and will not fall
back this fall.
Palestine will fall back at 00:00, not 01:00. (Thanks to Steffen Thorsen.)
Changes affecting API
The types of the global variables 'timezone' and 'altzone' (if present)
have been changed back to 'long'. This is required for 'timezone'
by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
These variables were originally 'long' in the tz code, but were
mistakenly changed to 'time_t' in 1987; nobody reported the
incompatibility until now. The difference matters on x32, where
'long' is 32 bits and 'time_t' is 64. (Thanks to Elliott Hughes.)
Changes affecting the build procedure
Avoid long strings in leapseconds.awk to work around a mawk bug.
(Thanks to Cyril Baurand.)
Changes affecting documentation and commentary
New file 'NEWS' that contains release notes like this one.
Paraguay's law does not specify DST transition time; 00:00 is customary.
(Thanks to Waldemar Villamayor-Venialbo.)
Minor capitalization fixes.
Changes affecting version-control only
The experimental GitHub repository now contains annotated and
signed tags for recent releases, e.g., '2013e' for Release 2013e.
Releases are tagged starting with 2012e; earlier releases were
done differently, and tags would either not have a simple name or
not exactly match what was released.
'make set-timestamps' is now simpler and a bit more portable.
Release 2013e - 2013-09-19 23:50:04 -0700
Changes affecting near-future timestamps
This year Fiji will start DST on October 27, not October 20.
(Thanks to David Wheeler for the heads-up.) For now, guess that
Fiji will continue to spring forward the Sunday before the fourth
Monday in October.
Changes affecting current and future time zone abbreviations
Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian
time zone abbreviations since 1932. (Thanks to George Ziegler,
Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and
Benny Lin.) This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura,
Asia/Makassar, and Asia/Pontianak.
Use ART (UT -03, standard time), rather than WARST (also -03, but
daylight saving time) for San Luis, Argentina since 2009.
Changes affecting Godthåb timestamps after 2037 if version mismatch
Allow POSIX-like TZ strings where the transition time's hour can
range from -167 through 167, instead of the POSIX-required 0
through 24. E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
new Fiji rules. This is a more compact way to represent
far-future timestamps for America/Godthab, America/Santiago,
Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
Pacific/Easter, and Pacific/Fiji. Other zones are unaffected by
this change. (Derived from a suggestion by Arthur David Olson.)
Allow POSIX-like TZ strings where daylight saving time is in
effect all year. E.g., TZ='WART4WARST,J1/0,J365/25' for Western
Argentina Summer Time all year. This supports a more compact way
to represent the 2013d data for America/Argentina/San_Luis.
Because of the change for San Luis noted above this change does not
affect the current data. (Thanks to Andrew Main (Zefram) for
suggestions that improved this change.)
Where these two TZ changes take effect, there is a minor extension
to the tz file format in that it allows new values for the
embedded TZ-format string, and the tz file format version number
has therefore been increased from 2 to 3 as a precaution.
Version-2-based client code should continue to work as before for
all timestamps before 2038. Existing version-2-based client code
(tzcode, GNU/Linux, Solaris) has been tested on version-3-format
files, and typically works in practice even for timestamps after
2037; the only known exception is America/Godthab.
Changes affecting timestamps before 1970
Pacific/Johnston is now a link to Pacific/Honolulu. This corrects
some errors before 1947.
Some zones have been turned into links, when they differ from existing
zones only in older data entries that were likely invented or that
differ only in LMT or transitions from LMT. These changes affect
only timestamps before 1943. The affected zones are:
Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
America/Grenada, America/Guadeloupe, America/Marigot,
America/Montserrat, America/St_Barthelemy, America/St_Kitts,
America/St_Lucia, America/St_Thomas, America/St_Vincent,
America/Tortola, and Europe/Vaduz. (Thanks to Alois Treindl for
confirming that the old Europe/Vaduz zone was wrong and the new
link is better for WWII-era times.)
Change Kingston Mean Time from -5:07:12 to -5:07:11. This affects
America/Cayman, America/Jamaica and America/Grand_Turk timestamps
from 1890 to 1912.
Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
This affects Europe/Zurich timestamps from 1853 to 1894. (Thanks
to Alois Treindl.)
Change the date of the circa-1850 Zurich transition from 1849-09-12
to 1853-07-16, overriding Shanks with data from Messerli about
postal and telegraph time in Switzerland.
Changes affecting time zone abbreviations before 1970
For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932,
as Jakarta was called Batavia back then.
Changes affecting API
The 'zic' command now outputs a dummy transition when far-future
data can't be summarized using a TZ string, and uses a 402-year
window rather than a 400-year window. For the current data, this
affects only the Asia/Tehran file. It does not affect any of the
timestamps that this file represents, so zdump outputs the same
information as before. (Thanks to Andrew Main (Zefram).)
The 'date' command has a new '-r' option, which lets you specify
the integer time to display, a la FreeBSD.
The 'tzselect' command has two new options '-c' and '-n', which lets you
select a zone based on latitude and longitude.
The 'zic' command's '-v' option now warns about constructs that
require the new version-3 binary file format. (Thanks to Arthur
David Olson for the suggestion.)
Support for floating-point time_t has been removed.
It was always dicey, and POSIX no longer requires it.
(Thanks to Eric Blake for suggesting to the POSIX committee to
remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
Heninger, Arthur David Olson, and Alois Treindl, for reporting
bugs and elucidating some of the corners of the old floating-point
implementation.)
The signatures of 'offtime', 'timeoff', and 'gtime' have been
changed back to the old practice of using 'long' to represent UT
offsets. This had been inadvertently and mistakenly changed to
'int_fast32_t'. (Thanks to Christos Zoulas.)
The code avoids undefined behavior on integer overflow in some
more places, including gmtime, localtime, mktime and zdump.
Changes affecting the zdump utility
zdump now outputs "UT" when referring to Universal Time, not "UTC".
"UTC" does not make sense for timestamps that predate the introduction
of UTC, whereas "UT", a more generic term, does. (Thanks to Steve Allen
for clarifying UT vs UTC.)
Data changes affecting behavior of tzselect and similar programs
Country code BQ is now called the more common name "Caribbean Netherlands"
rather than the more official "Bonaire, St Eustatius & Saba".
Remove from zone.tab the names America/Montreal, America/Shiprock,
and Antarctica/South_Pole, as they are equivalent to existing
same-country-code zones for post-1970 timestamps. The data entries for
these names are unchanged, so the names continue to work as before.
Changes affecting code internals
zic -c now runs way faster on 64-bit hosts when given large numbers.
zic now uses vfprintf to avoid allocating and freeing some memory.
tzselect now computes the list of continents from the data,
rather than have it hard-coded.
Minor changes pacify GCC 4.7.3 and GCC 4.8.1.
Changes affecting the build procedure
The 'leapseconds' file is now generated automatically from a
new file 'leap-seconds.list', which is a copy of
<ftp://ftp.nist.gov/pub/time/leap-seconds.list>
A new source file 'leapseconds.awk' implements this.
The goal is simplification of the future maintenance of 'leapseconds'.
When building the 'posix' or 'right' subdirectories, if the
subdirectory would be a copy of the default subdirectory, it is
now made a symbolic link if that is supported. This saves about
2 MB of file system space.
The links America/Shiprock and Antarctica/South_Pole have been
moved to the 'backward' file. This affects only nondefault builds
that omit 'backward'.
Changes affecting version-control only
.gitignore now ignores 'date'.
Changes affecting documentation and commentary
Changes to the 'tzfile' man page
It now mentions that the binary file format may be extended in
future versions by appending data.
It now refers to the 'zdump' and 'zic' man pages.
Changes to the 'zic' man page
It lists conditions that elicit a warning with '-v'.
It says that the behavior is unspecified when duplicate names
are given, or if the source of one link is the target of another.
Its examples are updated to match the latest data.
The definition of white space has been clarified slightly.
(Thanks to Michael Deckers.)
Changes to the 'Theory' file
There is a new section about the accuracy of the tz database,
describing the many ways that errors can creep in, and
explaining why so many of the pre-1970 timestamps are wrong or
misleading (thanks to Steve Allen, Lester Caine, and Garrett
Wollman for discussions that contributed to this).
The 'Theory' file describes LMT better (this follows a
suggestion by Guy Harris).
It refers to the 2013 edition of POSIX rather than the 2004 edition.
It's mentioned that excluding 'backward' should not affect the
other data, and it suggests at least one zone.tab name per
inhabited country (thanks to Stephen Colebourne).
Some longstanding restrictions on names are documented, e.g.,
'America/New_York' precludes 'America/New_York/Bronx'.
It gives more reasons for the 1970 cutoff.
It now mentions which time_t variants are supported, such as
signed integer time_t. (Thanks to Paul Goyette for reporting
typos in an experimental version of this change.)
(Thanks to Philip Newton for correcting typos in these changes.)
Documentation and commentary is more careful to distinguish UT in
general from UTC in particular. (Thanks to Steve Allen.)
Add a better source for the Zurich 1894 transition.
(Thanks to Pierre-Yves Berger.)
Update shapefile citations in tz-link.htm. (Thanks to Guy Harris.)
Release 2013d - 2013-07-05 07:38:01 -0700
Changes affecting future timestamps:
Morocco's midsummer transitions this year are July 7 and August 10,
not July 9 and August 8. (Thanks to Andrew Paprocki.)
Israel now falls back on the last Sunday of October.
(Thanks to Ephraim Silverberg.)
Changes affecting past timestamps:
Specify Jerusalem's location more precisely; this changes the pre-1880
times by 2 s.
Changing affecting metadata only:
Fix typos in the entries for country codes BQ and SX.
Changes affecting code:
Rework the code to fix a bug with handling Australia/Macquarie on
32-bit hosts (thanks to Arthur David Olson).
Port to platforms like NetBSD, where time_t can be wider than long.
Add support for testing time_t types other than the system's.
Run 'make check_time_t_alternatives' to try this out.
Currently, the tests fail for unsigned time_t;
this should get fixed at some point.
Changes affecting documentation and commentary:
Deemphasize the significance of national borders.
Update the zdump man page.
Remove obsolete NOID comment (thanks to Denis Excoffier).
Update several URLs and comments in the web pages.
Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler).
Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka).
Release 2013c - 2013-04-19 16:17:40 -0700
Changes affecting current and future timestamps:
Palestine observed DST starting March 29, 2013. (Thanks to
Steffen Thorsen.) From 2013 on, Gaza and Hebron both observe DST,
with the predicted rules being the last Thursday in March at 24:00
to the first Friday on or after September 21 at 01:00.
Assume that the recent change to Paraguay's DST rules is permanent,
by moving the end of DST to the 4th Sunday in March every year.
(Thanks to Carlos Raúl Perasso.)
Changes affecting past timestamps:
Fix some historical data for Palestine to agree with that of
timeanddate.com, as follows:
The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not
00:00 Apr 1.
The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not
02:00.
The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27.
The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2.
The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01.
The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00.
Fix times of habitation for Macquarie to agree with the Tasmania
Parks & Wildlife Service history, which indicates that permanent
habitation was 1899-1919 and 1948 on.
Changing affecting metadata only:
Macquarie Island is politically part of Australia, not Antarctica.
(Thanks to Tobias Conradi.)
Sort Macquarie more consistently with other parts of Australia.
(Thanks to Tim Parenti.)
Release 2013b - 2013-03-10 22:33:40 -0700
Changes affecting current and future timestamps:
Haiti uses US daylight-saving rules this year, and presumably future years.
This changes timestamps starting today. (Thanks to Steffen Thorsen.)
Paraguay will end DST on March 24 this year.
(Thanks to Steffen Thorsen.) For now, assume it's just this year.
Morocco does not observe DST during Ramadan;
try to predict Ramadan in Morocco as best we can.
(Thanks to Erik Homoet for the heads-up.)
Changes affecting commentary:
Update URLs in tz-link page. Add URLs for webOS, BB10, iOS.
Update URL for Solaris. Mention Internet RFC 6557.
Update Internet RFCs 2445->5545, 2822->5322.
Switch from FTP to HTTP for Internet RFCs.
Release 2013a - 2013-02-27 09:20:35 -0800
Change affecting binary data format:
The zone offset at the end of version-2-format zone files is now
allowed to be 24:00, as per POSIX.1-2008. (Thanks to Arthur David Olson.)
Changes affecting current and future timestamps:
Chile's 2013 rules, and we guess rules for 2014 and later, will be
the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC.
(Thanks to Steffen Thorsen and Robert Elz.)
New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen.
(Thanks to Tobias Conradi and Arthur David Olson.)
Many changes affect historical timestamps before 1940.
These were deduced from: Milne J. Civil time. Geogr J. 1899
Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.
Changes affecting the code:
Fix zic bug that mishandled Egypt's 2010 changes (this also affected
the data). (Thanks to Arthur David Olson.)
Fix localtime bug when time_t is unsigned and data files were generated
by a signed time_t system. (Thanks to Doug Bailey for reporting and
to Arthur David Olson for fixing.)
Allow the email address for bug reports to be set by the packager.
The default is [email protected], as before. (Thanks to Joseph S. Myers.)
Update HTML checking to be compatible with Ubuntu 12.10.
Check that files are a safe subset of ASCII. At some point we may
relax this requirement to a safe subset of UTF-8. Without the
check, some non-UTF-8 encodings were leaking into the distribution.
Commentary changes:
Restore a comment about copyright notices that was inadvertently deleted.
(Thanks to Arthur David Olson.)
Improve the commentary about which districts observe what times
in Russia. (Thanks to Oscar van Vlijmen and Arthur David Olson.)
Add web page links to tz.js.
Add "Run by the Monkeys" to tz-art. (Thanks to Arthur David Olson.)
Release 2012j - 2012-11-12 18:34:49 -0800
Libya moved to CET this weekend, but with DST planned next year.
(Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.)
Signatures now have the extension .asc, not .sign, as that's more
standard. (Thanks to Phil Pennock.)
The output of 'zdump --version', and of 'zic --version', now
uses a format that is more typical for --version.
(Thanks to Joseph S. Myers.)
The output of 'tzselect --help', 'zdump --help', and 'zic --help'
now uses [email protected] rather than the old elsie address.
zic -v now complains about abbreviations that are less than 3
or more than 6 characters, as per POSIX. Formerly, it checked
for abbreviations that were more than 3.
'make public' no longer puts its temporary directory under /tmp,
and uses the just-built zic rather than the system zic.
Various fixes to documentation and commentary.
Release 2012i - 2012-11-03 12:57:09 -0700
Cuba switches from DST tomorrow at 01:00. (Thanks to Steffen Thorsen.)
Linker flags can now be specified via LDFLAGS.
AWK now defaults to 'awk', not 'nawk'.
The shell in tzselect now defaults to /bin/bash, but this can
be overridden by specifying KSHELL.
The main web page now mentions the unofficial GitHub repository.
(Thanks to Mike Frysinger.)
Tarball signatures can now be built by running 'make signatures'.
There are also new makefile rules 'tarballs', 'check_public', and
separate makefile rules for each tarball and signature file.
A few makefile rules are now more portable to strict POSIX.
The main web page now lists the canonical IANA URL.
Release 2012h - 2012-10-26 22:49:10 -0700
Bahia no longer has DST. (Thanks to Kelley Cook.)
Tocantins has DST. (Thanks to Rodrigo Severo.)
Israel has new DST rules next year. (Thanks to Ephraim Silverberg.)
Jordan stays on DST this winter. (Thanks to Steffen Thorsen.)
Web page updates.
More C modernization, except that at Arthur David Olson's suggestion
the instances of 'register' were kept.
Release 2012g - 2012-10-17 20:59:45 -0700
Samoa fall 2012 and later. (Thanks to Nicholas Pereira and Robert Elz.)
Palestine fall 2012. (Thanks to Steffen Thorsen.)
Assume C89.
To attack the version-number problem, this release ships the file
'Makefile' (which contains the release number) in both the tzcode and
the tzdata tarballs. The two Makefiles are identical, and should be
identical in any matching pair of tarballs, so it shouldn't matter
which order you extract the tarballs. Perhaps we can come up with a
better version-number scheme at some point; this scheme does have the
virtue of not adding more files.
Release 2012f - 2012-09-12 23:17:03 -0700
* australasia (Pacific/Fiji): Fiji DST is October 21 through January
20 this year. (Thanks to Steffen Thorsen.)
Release 2012e - 2012-08-02 20:44:55 -0700
* australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14.
(Thanks to Steffen Thorsen.)
* Use a single version number for both code and data.
* .gitignore: New file.
* Remove trailing white space.
Release code2012c-data2012d - 2012-07-19 16:35:33 -0700
Changes for Morocco's timestamps, which take effect in a couple of
hours, along with infrastructure changes to accommodate how the tz
code and data are released on IANA.
Release data2012c - 2012-03-27 12:17:25 -0400
africa
Summer time changes for Morocco (to start late April 2012)
asia
Changes for 2012 for Gaza & the West Bank (Hebron) and Syria
northamerica
Haiti following US/Canada rules for 2012 (and we're assuming,
for now anyway, for the future).
Release 2012b - 2012-03-02 12:29:15 +0700
There is just one change to tzcode2012b (compared with 2012a):
the Makefile that was accidentally included with 2012a has been
replaced with the version that should have been there, which is
identical with the previous version (from tzcode2011i).
There are just two changes in tzdata2012b compared with 2012a.
Most significantly, summer time in Cuba has been delayed 3 weeks
(now starts April 1 rather than March 11). Since Mar 11 (the old start
date, as listed in 2012a) is just a little over a week away, this
change is urgent.
Less importantly, an excess tab in one of the changes in zone.tab
in 2012a has been removed.
Release 2012a - 2012-03-01 18:28:10 +0700
The changes in tzcode2012a (compared to the previous version, 2011i)
are entirely to the README and tz-art.htm and tz-link.htm files, if
none of those concern you, you can ignore the code update. The changes
reflect the changed addresses for the mailing list and the code and
data distribution points & methods (and a link to DateTime::TimeZone::Tzfile
has been added to tz-link.htm).
In tzdata2012a (compared to the previous release, which was 2011n)
the major changes are:
Chile 2011/2012 and 2012/2013 summer time date adjustments.
Falkland Islands onto permanent summer time (we're assuming for the
foreseeable future, though 2012 is all we're fairly certain of.)
Armenia has abolished Summer Time.
Tokelau jumped the International Date Line back last December
(just the same as their near neighbour, Samoa).
America/Creston is a new zone for a small area of British Columbia
There will be a leapsecond 2012-06-30 23:59:60 UTC.
Other minor changes are:
Corrections to 1918 Canadian summer time end dates.
Updated URL for UK time zone history (in comments)
A few typos in Le Corre's list of free French place names (comments)
Release data2011n - 2011-10-30 14:57:54 +0700
There are three changes of note - most urgently, Cuba (America/Havana)
has extended summer time by two weeks, now to end on Nov 13, rather than
the (already past) Oct 30. Second, the Pridnestrovian Moldavian Republic
(Europe/Tiraspol) decided not to split from the rest of Moldova after
all, and consequently that zone has been removed (again) and reinstated
in the "backward" file as a link to Europe/Chisinau. And third, the
end date for Fiji's summer time this summer was moved forward from the
earlier planned Feb 26, to Jan 22.
Apart from that, Moldova (MD) returns to a single entry in zone.tab
(and the incorrect syntax that was in the 2011m version of that file
is so fixed - it would have been fixed in a different way had this
change not happened - that's the "missing" sccs version id).
Release data2011m - 2011-10-24 21:42:16 +0700
In particular, the typos in comments in the data (2011-11-17 should have
been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that
Tim Parenti noted) have been fixed, and the change for Ukraine has been
made in all 4 Ukrainian zones, rather than just Europe/Kiev
(again, thanks to Tim Parenti, and also Denys Gavrysh).
In addition, I added Europe/Tiraspol to zone.tab.
This time, all the files have new version numbers... (including the files
otherwise unchanged in 2011m that were changed in 2011l but didn't get new
version numbers there...)
Release data2011l - 2011-10-10 11:15:43 +0700
There are just 2 changes that cause different generated tzdata files from
zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil
is included, but commented out. Compared with the diff I sent out last week,
this version also includes attributions for the sources for the changes
(in much the same format as ado used, but the html tags have not been
checked, verified, or used in any way at all, so if there are errors there,
please let me know.)
Release data2011k - 2011-09-20 17:54:03 -0400
[not summarized]
Release data2011j - 2011-09-12 09:22:49 -0400
(contemporary changes for Samoa; past changes for Kenya, Uganda, and
Tanzania); there are also two spelling corrections to comments in
the australasia file (with thanks to Christos Zoulas).
Release 2011i - 2011-08-29 05:56:32 -0400
[not summarized]
Release data2011h - 2011-06-15 18:41:48 -0400
Russia and Curaçao changes
Release 2011g - 2011-04-25 09:07:22 -0400
update the rules for Egypt to reflect its abandonment of DST this year
Release 2011f - 2011-04-06 17:14:53 -0400
[not summarized]
Release 2011e - 2011-03-31 16:04:38 -0400
Morocco, Chile, and tz-link changes
Release 2011d - 2011-03-14 09:18:01 -0400
changes that impact present-day timestamps in Cuba, Samoa, and Turkey
Release 2011c - 2011-03-07 09:30:09 -0500
These do affect current timestamps in Chile and Annette Island, Canada.
Release 2011b - 2011-02-07 08:44:50 -0500
[not summarized]
Release 2011a - 2011-01-24 10:30:16 -0500
[not summarized]
Release data2010o - 2010-11-01 09:18:23 -0400
change to the end of DST in Fiji in 2011
Release 2010n - 2010-10-25 08:19:17 -0400
[not summarized]
Release 2010m - 2010-09-27 09:24:48 -0400
Hong Kong, Vostok, and zic.c changes
Release 2010l - 2010-08-16 06:57:25 -0400
[not summarized]
Release 2010k - 2010-07-26 10:42:27 -0400
[not summarized]
Release 2010j - 2010-05-10 09:07:48 -0400
changes for Bahía de Banderas and for version naming
Release data2010i - 2010-04-16 18:50:45 -0400
the end of DST in Morocco on 2010-08-08
Release data2010h - 2010-04-05 09:58:56 -0400
[not summarized]
Release data2010g - 2010-03-24 11:14:53 -0400
[not summarized]
Release 2010f - 2010-03-22 09:45:46 -0400
[not summarized]
Release data2010e - 2010-03-08 14:24:27 -0500
corrects the Dhaka bug found by Danvin Ruangchan
Release data2010d - 2010-03-06 07:26:01 -0500
[not summarized]
Release 2010c - 2010-03-01 09:20:58 -0500
changes including KRE's suggestion for earlier initialization of
"goahead" and "goback" structure elements
Release code2010a - 2010-02-16 10:40:04 -0500
[not summarized]
Release data2010b - 2010-01-20 12:37:01 -0500
Mexico changes
Release data2010a - 2010-01-18 08:30:04 -0500
changes to Dhaka
Release data2009u - 2009-12-26 08:32:28 -0500
changes to DST in Bangladesh
Release 2009t - 2009-12-21 13:24:27 -0500
[not summarized]
Release data2009s - 2009-11-14 10:26:32 -0500
(cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change
Release 2009r - 2009-11-09 10:10:31 -0500
"antarctica" and "tz-link.htm" changes
Release 2009q - 2009-11-02 09:12:40 -0500
with two corrections as reported by Eric Muller and Philip Newton
Release data2009p - 2009-10-23 15:05:27 -0400
Argentina (including San Luis) changes (with the correction from
Mariano Absatz)
Release data2009o - 2009-10-14 16:49:38 -0400
Samoa (commentary only), Pakistan, and Bangladesh changes
Release data2009n - 2009-09-22 15:13:38 -0400
added commentary for Argentina and a change to the end of DST in
2009 in Pakistan
Release data2009m - 2009-09-03 10:23:43 -0400
Samoa and Palestine changes
Release data2009l - 2009-08-14 09:13:07 -0400
Samoa (comments only) and Egypt
Release 2009k - 2009-07-20 09:46:08 -0400
[not summarized]
Release data2009j - 2009-06-15 06:43:59 -0400
Bangladesh change (with a short turnaround since the DST change is
impending)
Release 2009i - 2009-06-08 09:21:22 -0400
updating for DST in Bangladesh this year
Release 2009h - 2009-05-26 09:19:14 -0400
[not summarized]
Release data2009g - 2009-04-20 16:34:07 -0400
Cairo
Release data2009f - 2009-04-10 11:00:52 -0400
correct DST in Pakistan
Release 2009e - 2009-04-06 09:08:11 -0400
[not summarized]
Release 2009d - 2009-03-23 09:38:12 -0400
Morocco, Tunisia, Argentina, and American Astronomical Society changes
Release data2009c - 2009-03-16 09:47:51 -0400
change to the start of Cuban DST
Release 2009b - 2009-02-09 11:15:22 -0500
[not summarized]
Release 2009a - 2009-01-21 10:09:39 -0500
[not summarized]
Release data2008i - 2008-10-21 12:10:25 -0400
southamerica and zone.tab files, with Argentina DST rule changes and
United States zone reordering and recommenting
Release 2008h - 2008-10-13 07:33:56 -0400
[not summarized]
Release 2008g - 2008-10-06 09:03:18 -0400
Fix a broken HTML anchor and update Brazil's DST transitions;
there's also a slight reordering of information in tz-art.htm.
Release data2008f - 2008-09-09 22:33:26 -0400
[not summarized]
Release 2008e - 2008-07-28 14:11:17 -0400
changes by Arthur David Olson and Jesper Nørgaard Welen
Release data2008d - 2008-07-07 09:51:38 -0400
changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo
Release data2008c - 2008-05-19 17:48:03 -0400
Pakistan, Morocco, and Mongolia
Release data2008b - 2008-03-24 08:30:59 -0400
including renaming Asia/Calcutta to Asia/Kolkata, with a backward
link provided
Release 2008a - 2008-03-08 05:42:16 -0500
[not summarized]
Release 2007k - 2007-12-31 10:25:22 -0500
most importantly, changes to the "southamerica" file based on
Argentina's readoption of daylight saving time
Release 2007j - 2007-12-03 09:51:01 -0500
1. eliminate the "P" (parameter) macro;
2. the "noncontroversial" changes circulated on the time zone
mailing list (less the changes to "logwtmp.c");
3. eliminate "too many transition" errors when "min" is used in time
zone rules;
4. changes by Paul Eggert (including updated information for Venezuela).
Release data2007i - 2007-10-30 10:28:11 -0400
changes for Cuba and Syria
Release 2007h - 2007-10-01 10:05:51 -0400
changes by Paul Eggert, as well as an updated link to the ICU
project in tz-link.htm
Release 2007g - 2007-08-20 10:47:59 -0400
changes by Paul Eggert
The "leapseconds" file has been updated to incorporate the most
recent International Earth Rotation and Reference Systems Service
(IERS) bulletin.
There's an addition to tz-art.htm regarding the television show "Medium".
Release 2007f - 2007-05-07 10:46:46 -0400
changes by Paul Eggert (including Haiti, Turks and Caicos, and New
Zealand)
changes to zic.c to allow hour values greater than 24 (along with
Paul's improved time value overflow checking)
Release 2007e - 2007-04-02 10:11:52 -0400
Syria and Honduras changes by Paul Eggert
zic.c variable renaming changes by Arthur David Olson
Release 2007d - 2007-03-20 08:48:30 -0400
changes by Paul Eggert
the elimination of white space at the ends of lines
Release 2007c - 2007-02-26 09:09:37 -0500
changes by Paul Eggert
Release 2007b - 2007-02-12 09:34:20 -0500
Paul Eggert's proposed change to the quotation handling logic in zic.c.
changes to the commentary in "leapseconds" reflecting the IERS
announcement that there is to be no positive leap second at the end
of June 2007.
Release 2007a - 2007-01-08 12:28:29 -0500
changes by Paul Eggert
Derick Rethans's Asmara change
Oscar van Vlijmen's Easter Island local mean time change
symbolic link changes
Release 2006p - 2006-11-27 08:54:27 -0500
changes by Paul Eggert
Release 2006o - 2006-11-06 09:18:07 -0500
changes by Paul Eggert
Release 2006n - 2006-10-10 11:32:06 -0400
changes by Paul Eggert
Release 2006m - 2006-10-02 15:32:35 -0400
changes for Uruguay, Palestine, and Egypt by Paul Eggert
(minimalist) changes to zic.8 to clarify "until" information
Release data2006l - 2006-09-18 12:58:11 -0400
Paul's best-effort work on this coming weekend's Egypt time change
Release 2006k - 2006-08-28 12:19:09 -0400
changes by Paul Eggert
Release 2006j - 2006-08-21 09:56:32 -0400
changes by Paul Eggert
Release code2006i - 2006-08-07 12:30:55 -0400
localtime.c fixes
Ken Pizzini's conversion script
Release code2006h - 2006-07-24 09:19:37 -0400
adds public domain notices to four files
includes a fix for transition times being off by a second
adds a new recording to the "arts" file (information courtesy Colin Bowern)
Release 2006g - 2006-05-08 17:18:09 -0400
northamerica changes by Paul Eggert
Release 2006f - 2006-05-01 11:46:00 -0400
a missing version number problem is fixed (with thanks to Bradley
White for catching the problem)
Release 2006d - 2006-04-17 14:33:43 -0400
changes by Paul Eggert
added new items to tz-arts.htm that were found by Paul
Release 2006c - 2006-04-03 10:09:32 -0400
two sets of data changes by Paul Eggert
a fencepost error fix in zic.c
changes to zic.c and the "europe" file to minimize differences
between output produced by the old 32-bit zic and the new 64-bit
version
Release 2006b - 2006-02-20 10:08:18 -0500
[tz32code2006b + tz64code2006b + tzdata2006b]
64-bit code
All SCCS IDs were bumped to "8.1" for this release.
Release 2006a - 2006-01-30 08:59:31 -0500
changes by Paul Eggert (in particular, Indiana time zone moves)
an addition to the zic manual page to describe how special-case
transitions are handled
Release 2005r - 2005-12-27 09:27:13 -0500
Canadian changes by Paul Eggert
They also add "<pre>" directives to time zone data files and reflect
changes to warning message logic in "zdump.c" (but with calls to
"gettext" kept unbundled at the suggestion of Ken Pizzini).
Release 2005q - 2005-12-13 09:17:09 -0500
Nothing earth-shaking here:
1. Electronic mail addresses have been removed.
2. Casts of the return value of exit have been removed.
3. Casts of the argument of is.* macros have been added.
4. Indentation in one section of zic.c has been fixed.
5. References to dead URLs in the data files have been dealt with.
Release 2005p - 2005-12-05 10:30:53 -0500
"systemv", "tz-link.htm", and "zdump.c" changes
(less the casts of arguments to the is* macros)
Release 2005o - 2005-11-28 10:55:26 -0500
Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert
zdump.c lint fixes by Arthur David Olson
Release 2005n - 2005-10-03 09:44:09 -0400
changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan
et al. changes)
Release 2005m - 2005-08-29 12:15:40 -0400
changes by Paul Eggert (with a small tweak to the tz-art change)
a declaration of an unused variable has been removed from zdump.c
Release 2005l - 2005-08-22 12:06:39 -0400
changes by Paul Eggert
overflow/underflow checks by Arthur David Olson, minus changes to
the "Theory" file about the pending addition of 64-bit data (I grow
less confident of the changes being accepted with each passing day,
and the changes no longer increase the data files nine-fold--there's
less than a doubling in size by my local Sun's reckoning)
Release 2005k - 2005-07-14 14:14:24 -0400
The "leapseconds" file has been edited to reflect the recently
announced leap second at the end of 2005.
I've also deleted electronic mail addresses from the files as an
anti-spam measure.
Release 2005j - 2005-06-13 14:34:13 -0400
These reflect changes to limit the length of time zone abbreviations
and the characters used in those abbreviations.
There are also changes to handle POSIX-style "quoted" timezone
environment variables.
The changes were circulated on the time zone mailing list; the only
change since then was the removal of a couple of minimum-length of
abbreviation checks.
Release data2005i - 2005-04-21 15:04:16 -0400
changes (most importantly to Nicaragua and Haiti) by Paul Eggert
Release 2005h - 2005-04-04 11:24:47 -0400
changes by Paul Eggert
minor changes to Makefile and zdump.c to produce more useful output
when doing a "make typecheck"
Release 2005g - 2005-03-14 10:11:21 -0500
changes by Paul Eggert (a change to current DST rules in Uruguay and
an update to a link to time zone software)
Release 2005f - 2005-03-01 08:45:32 -0500
data and documentation changes by Paul Eggert
Release 2005e - 2005-02-10 15:59:44 -0500
[not summarized]
Release code2005d - 2005-01-31 09:21:47 -0500
make zic complain about links to links if the -v flag is used
have "make public" do more code checking
add an include to "localtime.c" for the benefit of gcc systems
Release 2005c - 2005-01-17 18:36:29 -0500
get better results when mktime runs on a system where time_t is double
changes to the data files (most importantly to Paraguay)
Release 2005b - 2005-01-10 09:19:54 -0500
Get localtime and gmtime working on systems with exotic time_t types.
Update the leap second commentary in the "leapseconds" file.
Release 2005a - 2005-01-01 13:13:44 -0500
[not summarized]
Release code2004i - 2004-12-14 13:42:58 -0500
Deal with systems where time_t is unsigned.
Release code2004h - 2004-12-07 11:40:18 -0500
64-bit-time_t changes
Release 2004g - 2004-11-02 09:06:01 -0500
update to Cuba (taking effect this weekend)
other changes by Paul Eggert
correction of the spelling of Oslo
changed versions of difftime.c and private.h
Release code2004f - 2004-10-21 10:25:22 -0400
Cope with wide-ranging tm_year values.
Release 2004e - 2004-10-11 14:47:21 -0400
Brazil/Argentina/Israel changes by Paul Eggert
changes to tz-link.htm by Paul
one small fix to Makefile
Release 2004d - 2004-09-22 08:27:29 -0400
Avoid overflow problems when TM_YEAR_BASE is added to an integer.
Release 2004c - 2004-08-11 12:06:26 -0400
asctime-related changes
(variants of) some of the documentation changes suggested by Paul Eggert
Release 2004b - 2004-07-19 14:33:35 -0400
data changes by Paul Eggert - most importantly, updates for Argentina
Release 2004a - 2004-05-27 12:00:47 -0400
changes by Paul Eggert
Handle DST transitions that occur at the end of a month in some
years but at the start of the following month in other years.
Add a copy of the correspondence that's the basis for claims about
DST in the Navajo Nation.
Release 2003e - 2003-12-15 09:36:47 -0500
changes by Arthur David Olson (primarily code changes)
changes by Paul Eggert (primarily data changes)
minor changes to "Makefile" and "northamerica" (in the latter case,
optimization of the "Toronto" rules)
Release 2003d - 2003-10-06 09:34:44 -0400
changes by Paul Eggert
Release 2003c - 2003-09-16 10:47:05 -0400
Fix bad returns in zic.c's inleap function.
Thanks to Bradley White for catching the problem!
Release 2003b - 2003-09-16 07:13:44 -0400
Add a "--version" option (and documentation) to the zic and zdump commands.
changes to overflow/underflow checking in zic
a localtime typo fix.
Update the leapseconds and tz-art.htm files.
Release 2003a - 2003-03-24 09:30:54 -0500
changes by Paul Eggert
a few additions and modifications to the tz-art.htm file
Release 2002d - 2002-10-15 13:12:42 -0400
changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab
There's also a new time zone quote in "tz-art.htm".
Release 2002c - 2002-04-04 11:55:20 -0500
changes by Paul Eggert
Change zic.c to avoid creating symlinks to files that don't exist.
Release 2002b - 2002-01-28 12:56:03 -0500
[These change notes are for Release 2002a, which was corrupted.
2002b was a corrected version of 2002a.]
changes by Paul Eggert
Update the "leapseconds" file to note that there'll be no leap
second at the end of June, 2002.
Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone.
Change to "difftime.c" to avoid sizeof problems.
Release 2001d - 2001-10-09 13:31:32 -0400
changes by Paul Eggert
Release 2001c - 2001-06-05 13:59:55 -0400
changes by Paul Eggert and Andrew Brown
Release 2001b - 2001-04-05 16:44:38 -0400
changes by Paul Eggert (modulo jnorgard's typo fix)
tz-art.htm has been HTMLified.
Release 2001a - 2001-03-13 12:57:44 -0500
changes by Paul Eggert
An addition to the "leapseconds" file: comments with the text of the
latest IERS leap second notice.
Trailing white space has been removed from data file lines, and
repeated spaces in "Rule Jordan" lines in the "asia" file have been
converted to tabs.
Release 2000h - 2000-12-14 15:33:38 -0500
changes by Paul Eggert
one typo fix in the "art" file
With providence, this is the last update of the millennium.
Release 2000g - 2000-10-10 11:35:22 -0400
changes by Paul Eggert
correction of John Mackin's name submitted by Robert Elz
Garry Shandling's Daylight Saving Time joke (!?!) from the recent
Emmy Awards broadcast.
Release 2000f - 2000-08-10 09:31:58 -0400
changes by Paul Eggert
Added information in "tz-art.htm" on a Seinfeld reference to DST.
Error checking and messages in the "yearistype" script have been
improved.
Release 2000e - 2000-07-31 09:27:54 -0400
data changes by Paul Eggert
a change to the default value of the defined constant HAVE_STRERROR
the addition of a Dave Barry quote on DST to the tz-arts file
Release 2000d - 2000-04-20 15:43:04 -0400
changes to the documentation and code of strftime for C99 conformance
a bug fix for date.c
These are based on (though modified from) changes by Paul Eggert.
Release 2000c - 2000-03-04 10:31:43 -0500
changes by Paul Eggert
Release 2000b - 2000-02-21 12:16:29 -0500
changes by Paul Eggert and Joseph Myers
modest tweaks to the tz-art.htm and tz-link.htm files
Release 2000a - 2000-01-18 09:21:26 -0500
changes by Paul Eggert
The two hypertext documents have also been renamed.
Release code1999i-data1999j - 1999-11-15 18:43:22 -0500
Paul Eggert's changes
additions to the "zic" manual page and the "Arts.htm" file
Release code1999h-data1999i - 1999-11-08 14:55:21 -0500
[not summarized]
Release data1999h - 1999-10-07 03:50:29 -0400
changes by Paul Eggert to "europe" (most importantly, fixing
Lithuania and Estonia)
Release 1999g - 1999-09-28 11:06:18 -0400
data changes by Paul Eggert (most importantly, the change for
Lebanon that buys correctness for this coming Sunday)
The "code" file contains changes to "Makefile" and "checktab.awk" to
allow better checking of time zone files before they are published.
Release 1999f - 1999-09-23 09:48:14 -0400
changes by Arthur David Olson and Paul Eggert
Release 1999e - 1999-08-17 15:20:54 -0400
changes circulated by Paul Eggert, although the change to handling
of DST-specifying timezone names has been commented out for now
(search for "XXX" in "localtime.c" for details). These files also
do not make any changes to the start of DST in Brazil.
In addition to Paul's changes, there are updates to "Arts.htm" and
cleanups of URLs.
Release 1999d - 1999-03-30 11:31:07 -0500
changes by Paul Eggert
The Makefile's "make public" rule has also been changed to do a test
compile of each individual time zone data file (which should help
avoid problems such as the one we had with Nicosia).
Release 1999c - 1999-03-25 09:47:47 -0500
changes by Paul Eggert, most importantly the change for Chile.
Release 1999b - 1999-02-01 17:51:44 -0500
changes by Paul Eggert
code changes (suggested by Mani Varadarajan, mani at be.com) for
correct handling of symbolic links when building using a relative directory
code changes to generate correct messages for failed links
updates to the URLs in Arts.htm
Release 1999a - 1999-01-19 16:20:29 -0500
error message internationalizations and corrections in zic.c and
zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz,
to whom thanks!)
Release code1998h-data1998i - 1998-10-01 09:56:10 -0400
changes for Brazil, Chile, and Germany
support for use of "24:00" in the input files for the time zone compiler
Release code1998g-data1998h - 1998-09-24 10:50:28 -0400
changes by Paul Eggert
correction to a define in the "private.h" file
Release data1998g - 1998-08-11 03:28:35 -0000
[tzdata1998g.tar.gz is missing!]
Lithuanian change provided by mgedmin at pub.osf.it
Move creation of the GMT link with Etc/GMT to "etcetera" (from
"backward") to ensure that the GMT file is created even where folks
don't want the "backward" links (as suggested by Paul Eggert).
Release data1998f - 1998-07-20 13:50:00 -0000
[tzdata1998f.tar.gz is missing!]
Update the "leapseconds" file to include the newly announced
insertion at the end of 1998.
Release code1998f - 1998-06-01 10:18:31 -0400
addition to localtime.c by Guy Harris
Release 1998e - 1998-05-28 09:56:26 -0400
The Makefile is changed to produce zoneinfo-posix rather than
zoneinfo/posix, and to produce zoneinfo-leaps rather than
zoneinfo/right.
data changes by Paul Eggert
changes from Guy Harris to provide asctime_r and ctime_r
A usno1998 file (substantially identical to usno1997) has been added.
Release 1998d - 1998-05-14 11:58:34 -0400
changes to comments (in particular, elimination of references to CIA maps).
"Arts.htm", "WWW.htm", "asia", and "australasia" are the only places
where changes occur.
Release 1998c - 1998-02-28 12:32:26 -0500
changes by Paul Eggert (save the "French correction," on which I'll
wait for the dust to settle)
symlink changes
changes and additions to Arts.htm
Release 1998b - 1998-01-17 14:31:51 -0500
URL cleanups and additions
Release 1998a - 1998-01-13 12:37:35 -0500
changes by Paul Eggert
Release code1997i-data1997k - 1997-12-29 09:53:41 -0500
changes by Paul Eggert, with minor modifications from Arthur David
Olson to make the files more browser friendly
Release code1997h-data1997j - 1997-12-18 17:47:35 -0500
minor changes to put "TZif" at the start of each timezone information file
a rule has also been added to the Makefile so you can
make zones
to just recompile the zone information files (rather than doing a
full "make install" with its other effects).
Release data1997i - 1997-10-07 08:45:38 -0400
changes to Africa by Paul Eggert
Release code1997g-data1997h - 1997-09-04 16:56:54 -0400
corrections for Uruguay (and other locations)
Arthur David Olson's simple-minded fix allowing mktime to both
correctly handle leap seconds and correctly handle tm_sec values
upon which arithmetic has been performed.
Release code1997f-data1997g - 1997-07-19 13:15:02 -0400
Paul Eggert's updates
a small change to a function prototype;
"Music" has been renamed "Arts.htm", HTMLified, and augmented to
include information on Around the World in Eighty Days.
Release code1997e-data1997f - 1997-05-03 18:52:34 -0400
fixes to zic's error handling
changes inspired by the item circulated on Slovenia
The description of Web resources has been HTMLified for browsing
convenience.
A new piece of tz-related music has been added to the "Music" file.
Release code1997d-data1997e - 1997-03-29 12:48:52 -0500
Paul Eggert's latest suggestions
Release code1997c-data1997d - 1997-03-07 20:37:54 -0500
changes to "zic.c" to correct performance of the "-s" option
a new file "usno1997"
Release data1997c - 1997-03-04 09:58:18 -0500
changes in Israel
Release 1997b - 1997-02-27 18:34:19 -0500
The data file incorporates the 1997 leap second.
The code file incorporates Arthur David Olson's take on the
zic/multiprocessor/directory-creation situation.
Release 1997a - 1997-01-21 09:11:10 -0500
Paul Eggert's Antarctica (and other changes)
Arthur David Olson finessed the "getopt" issue by checking against
both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1
is returned while SunOS 5.5's manual says EOF is returned).
Release code1996o-data1996n - 1996-12-27 21:42:05 -0500
Paul Eggert's latest changes
Release code1996n - 1996-12-16 09:42:02 -0500
link snapping fix from Bruce Evans (via Garrett Wollman)
Release data1996m - 1996-11-24 02:37:34 -0000
[tzdata1996m.tar.gz is missing!]
Paul Eggert's batch of changes
Release code1996m-data1996l - 1996-11-05 14:00:12 -0500
No functional changes here; the files have simply been changed to
make more use of ISO style dates in comments. The names of the above
files now include the year in full.
Release code96l - 1996-09-08 17:12:20 -0400
tzcode96k was missing a couple of pieces.
Release 96k - 1996-09-08 16:06:22 -0400
the latest round of changes from Paul Eggert
the recent Year 2000 material
Release code96j - 1996-07-30 13:18:53 -0400
Set sp->typecnt as suggested by Timothy Patrick Murphy.
Release code96i - 1996-07-27 20:11:35 -0400
Paul's suggested patch for strftime %V week numbers
Release data96i - 1996-07-01 18:13:04 -0400
"northamerica" and "europe" changes by Paul Eggert
Release code96h - 1996-06-05 08:02:21 -0400
fix for handling transitions specified in Universal Time
Some "public domain" notices have also been added.
Release code96g - 1996-05-16 14:00:26 -0400
fix for the simultaneous-DST-and-zone-change challenge
Release data96h - 1996-05-09 17:40:51 -0400
changes by Paul Eggert
Release code96f-data96g - 1996-05-03 03:09:59 -0000
[tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!]
The changes get us some of the way to fixing the problems noted in Paul
Eggert's letter yesterday (in addition to a few others). The approach
has been to make zic a bit smarter about figuring out what time zone
abbreviations apply just after the time specified in the "UNTIL" part
of a zone line. Putting the smarts in zic means avoiding having
transition times show up in both "Zone" lines and "Rule" lines, which
in turn avoids multiple transition time entries in time zone files.
(This also makes the zic input files such as "europe" a bit shorter and
should ease maintenance.)
Release data96f - 1996-04-19 19:20:03 -0000
[tzdata96f.tar.gz is missing!]
The only changes are to the "northamerica" file; the time zone
abbreviation for Denver is corrected to MST (and MDT), and the
comments for Mexico have been updated.
Release data96e - 1996-03-19 17:37:26 -0500
Proposals by Paul Eggert, in particular the Portugal change that
comes into play at the end of this month.
Release data96d - 1996-03-18 20:49:39 -0500
[not summarized]
Release code96e - 1996-02-29 15:43:27 -0000
[tzcode96e.tar.gz is missing!]
internationalization changes and the fix to the documentation for strftime
Release code96d-data96c - 1996-02-12 11:05:27 -0500
The "code" file simply updates Bob Kridle's electronic address.
The "data" file updates rules for Mexico.
Release data96b - 1996-01-27 15:44:42 -0500
Kiribati change
Release code96c - 1996-01-16 16:58:15 -0500
leap-year streamlining and binary-search changes
fix to newctime.3
Release code96b - 1996-01-10 20:42:39 -0500
fixes and enhancements from Paul Eggert, including code that
emulates the behavior of recent versions of the SunOS "date"
command.
Release 96a - 1996-01-06 09:08:24 -0500
Israel updates
fixes to strftime.c for correct ISO 8601 week number generation,
plus support for two new formats ('G' and 'g') to give ISO 8601 year
numbers (which are not necessarily the same as calendar year numbers)
Release code95i-data95m - 1995-12-21 12:46:47 -0500
The latest revisions from Paul Eggert are included, the usno1995
file has been updated, and a new file ("WWW") covering useful URLs
has been added.
Release code95h-data95l - 1995-12-19 18:10:12 -0500
A simplification of a macro definition, a change to data for Sudan,
and (for last minute shoppers) notes in the "Music" file on the CD
"Old Man Time".
Release code95g-data95k - 1995-10-30 10:32:47 -0500
(slightly reformatted) 8-bit-clean proposed patch
minor patch: US/Eastern -> America/New_York
snapshot of the USNO's latest data ("usno1995")
some other minor cleanups
Release code95f-data95j - 1995-10-28 21:01:34 -0000
[tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!]
European cleanups
support for 64-bit time_t's
optimization in localtime.c
Release code95e - 1995-10-13 13:23:57 -0400
the mktime change to scan from future to past when trying to find time zone
offsets
Release data95i - 1995-09-26 10:43:26 -0400
For Canada/Central, guess that the Sun customer's "one week too
early" was just a approximation, and the true error is one month
too early. This is consistent with the rest of Canada.
Release data95h - 1995-09-21 11:26:48 -0400
latest changes from Paul Eggert
Release code95d - 1995-09-14 11:14:45 -0400
the addition of a "Music" file, which documents four recorded
versions of the tune "Save That Time".
Release data95g - 1995-09-01 17:21:36 -0400
"yearistype" correction
Release data95f - 1995-08-28 20:46:56 -0400
Paul Eggert's change to the australasia file
Release data95e - 1995-07-08 18:02:34 -0400
The only change is a leap second at the end of this year.
Thanks to Bradley White for forwarding news on the leap second.
Release data95d - 1995-07-03 13:26:22 -0400
Paul Eggert's changes
Release data95c - 1995-07-02 19:19:28 -0400
changes to "asia", "backward", "europe", and "southamerica"
(read: northamericacentrics need not apply)
Release code95c - 1995-03-13 14:00:46 -0500
one-line fix for sign extension problems in detzcode
Release 95b - 1995-03-04 11:22:38 -0500
Minor changes in both:
The "code" file contains a workaround for the lack of "unistd.h" in
Microsoft C++ version 7.
The "data" file contains a fixed "Link" for America/Shiprock.
Release 94h - 1994-12-10 12:51:14 -0500
The files:
* incorporate the changes to "zdump" and "date" to make changes to
the "TZ" environment variable permanent;
* incorporate the table changes by Paul Eggert;
* include (and document) support for universal time specifications in
data files - but do not (yet) include use of this feature in the
data files.
Think of this as "TZ Classic" - the software has been set up not to break if
universal time shows up in its input, and data entries have been
left as is so as not to break existing implementations.
Release data94f - 1994-08-20 12:56:09 -0400
(with thanks!) the latest data updates from Paul Eggert
Release data94e - 1994-06-04 13:13:53 -0400
[not summarized]
Release code94g - 1994-05-05 12:14:07 -0400
fix missing "optind.c" and a reference to it in the Makefile
Release code94f - 1994-05-05 13:00:33 -0000
[tzcode94f.tar.gz is missing!]
changes to avoid overflow in difftime, as well as changes to cope
with the 52/53 challenge in strftime
Release code94e - 1994-03-30 23:32:59 -0500
change for the benefit of PCTS
Release 94d - 1994-02-24 15:42:25 -0500
Avoid clashes with POSIX semantics for zones such as GMT+4.
Some other very minor housekeeping is also present.
Release code94c - 1994-02-10 08:52:40 -0500
Fix bug where mkdirs was broken unless you compile with
-fwritable-strings (which is generally losing to do).
Release 94b - 1994-02-07 10:04:33 -0500
work by Paul Eggert who notes:
I found another book of time zone histories by E W Whitman; it's not
as extensive as Shanks but has a few goodies of its own. I used it
to update the tables. I also fixed some more as a result of
correspondence with Adam David and Peter Ilieve, and move some stray
links from 'europe' to 'backward'. I corrected some scanning errors
in usno1989.
As far as the code goes, I fixed zic to allow years in the range
INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900.
And I cleaned up the zic documentation a little bit.
Release data94a - 1994-02-03 08:58:54 -0500
It simply incorporates the recently announced leap second into the
"leapseconds" file.
Release 93g - 1993-11-22 17:28:27 -0500
Paul Eggert has provided a good deal of historic information (based
on Shanks), and there are some code changes to deal with the buglets
that crawled out in dealing with the new information.
Release 93f - 1993-10-15 12:27:46 -0400
Paul Eggert's changes
Release 93e - 1993-09-05 21:21:44 -0400
This has updated data for Israel, England, and Kwajalein. There's
also an update to "zdump" to cope with Kwajalein's 24-hour jump.
Thanks to Paul Eggert and Peter Ilieve for the changes.
Release 93d - 1993-06-17 23:34:17 -0400
new fix and new data on Israel
Release 93c - 1993-06-06 19:31:55 -0400
[not summarized]
Release 93b - 1993-02-02 14:53:58 -0500
updated "leapseconds" file
Release 93 - 1993-01-08 07:01:06 -0500
At kre's suggestion, the package has been split in two - a code piece
(which also includes documentation) that's only of use to folks who
want to recompile things and a data piece useful to anyone who can
run "zic".
The new version has a few changes to the data files, a few
portability changes, and an off-by-one fix (with thanks to
Tom Karzes at deshaw.com for providing a description and a
solution).
Release 92c - 1992-11-21 17:35:36 -0000
[tz92c.tar.Z is missing!]
The fallout from the latest round of DST transitions.
There are changes for Portugal, Saskatchewan, and "Pacific-New";
there's also a change to "zic.c" that makes it portable to more systems.
Release 92 - 1992-04-25 18:17:03 -0000
[tz92.tar.Z is missing!]
By popular demand (well, at any rate, following a request by kre at munnari)
The 1989 update of the time zone package featured:
* POSIXization (including interpretation of POSIX-style TZ environment
variables, provided by Guy Harris),
* ANSIfication (including versions of "mktime" and "difftime"),
* SVIDulation (an "altzone" variable)
* MACHination (the "gtime" function)
* corrections to some time zone data (including corrections to the rules
for Great Britain and New Zealand)
* reference data from the United States Naval Observatory for folks who
want to do additional time zones
* and the 1989 data for Saudi Arabia.
(Since this code will be treated as "part of the implementation" in some
places and as "part of the application" in others, there's no good way to
name functions, such as timegm, that are not part of the proposed ANSI C
standard; such functions have kept their old, underscore-free names in this
update.)
And the "dysize" function has disappeared; it was present to allow
compilation of the "date" command on old BSD systems, and a version of "date"
is now provided in the package. The "date" command is not created when you
"make all" since it may lack options provided by the version distributed with
your operating system, or may not interact with the system in the same way
the native version does.
Since POSIX frowns on correct leap second handling, the default behavior of
the "zic" command (in the absence of a "-L" option) has been changed to omit
leap second information from its output files.
-----
Notes
This file contains copies of the part of each release announcement
that talks about the changes in that release. The text has been
adapted and reformatted for the purposes of this file.
Traditionally a release R consists of a pair of tarball files,
tzcodeR.tar.gz and tzdataR.tar.gz. However, some releases (e.g.,
code2010a, data2012c) consist of just one or the other tarball, and a
few (e.g., code2012c-data2012d) have tarballs with mixed version
numbers. Recent releases also come in an experimental format
consisting of a single tarball tzdb-R.tar.lz with extra data.
Release timestamps are taken from the release's commit (for newer,
Git-based releases), from the newest file in the tarball (for older
releases, where this info is available) or from the email announcing
the release (if all else fails; these are marked with a time zone
abbreviation of -0000 and an "is missing!" comment).
Earlier versions of the code and data were not announced on the tz
list and are not summarized here.
This file is in the public domain.
Local Variables:
coding: utf-8
End: