2022.3: Release of upstream tzdata 2022c

Version 2022.3

Upstream version 2022c released 2022-08-16T00:47:18+00:00

Briefly:

Work around awk bug in FreeBSD, macOS, etc. Improve tzselect on intercontinental
Zones.

2022.2: Release of upstream tzdata 2022b

Version 2022.2

Upstream version 2022b released 2022-08-10T22:38:32+00:00

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").

2022.1: Release of upstream tzdata 2022a

Version 2022.1

Upstream version 2022a released 2022-03-16T06:02:01+00:00

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.

2021.5: Release of upstream tzdata 2021e

Version 2021.5

Upstream version 2021e released 2021-10-22T01:41:00+00:00

Changes to future timestamps

Palestine will fall back 10-29 (not 10-30) at 01:00. (Thanks to P Chan and Heba Hemad.)

2021.4: Release of upstream tzdata 2021d

Version 2021.4

Upstream version 2021d released 2021-10-15T20:48:18+00:00

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.)

2021.3: Release of upstream tzdata 2021c

Version 2021.3

Upstream version 2021c released 2021-10-01T21:21:49+00:00

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 documentation

Distribute the SECURITY file (problem reported by Andreas Radke).

2021.2.post0: Release of upstream tzdata 2021b

Version 2021.2.post0

Upstream version 2021b released 2021-09-24T23:23:00+00:00

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.

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-
compatility 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 documentation

tzfile.5 better matches a draft successor to RFC 8536
https://datatracker.ietf.org/doc/draft-murchison-rfc8536bis/01/.

2021.2: Release of upstream tzdata 2021b

Version 2021.2

Upstream version 2021b released 2021-09-24T23:23:00+00:00

Briefly:

This is an intermediate release that cherry-picks only the changes to Jordan and
Samoa's DST. It will not match upstream 2021b, which includes many other
changes.

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.)

2021.1: Release of tzdata 2021a

Version 2021.1

Upstream version 2021a released 2021-01-24T18:54:57+00:00

Changes to future timestamps

South Sudan changes from +03 to +02 on 2021-02-01 at 00:00. (Thanks to Steffen
Thorsen.)

2020.5: Release of tzdata 2020e

Version 2020.5

Upstream version 2020e released 2020-12-22T23:14:34+00:00

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
• 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.