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* Updated: tzcode, tzdata 2022b
@ 2022-08-15  6:43 Cygwin tzcode/tzdata Maintainer
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From: Cygwin tzcode/tzdata Maintainer @ 2022-08-15  6:43 UTC (permalink / raw)
  To: Cygwin Announcements

The following packages have been upgraded in the Cygwin distribution:

* tzcode	2022b
* tzdata	2022b

The Time Zone Database (often called tz, tzdb, or zoneinfo) contains
data that represents the history of local time for many locations around
the world, and supports conversion of UTC time to local time at those
locations to allow display of those local times. It is updated
periodically to reflect changes made by political bodies to daylight
saving (summer time) rules, UTC offsets, and time zone boundaries.
The tzcode package provides the tzselect, zdump, and zic utilities.

For more details on changes, please see the announcement or below:

Release 2022b	2022-08-10 15:38:32 -0700


* 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.
* Iran plans to stop observing DST permanently, after it falls back
  on 2022-09-21.

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.
* 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.
* 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.
* 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.
  'zic -r @N' no longer outputs bad data when N < first transition.
* 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.
* 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 simultanously 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' 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.

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2022-08-15  6:43 Updated: tzcode, tzdata 2022b Cygwin tzcode/tzdata Maintainer

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