Updated: tzcode, tzdata 2022a

Cygwin tzcode/tzdata Maintainer Brian.Inglis@SystematicSW.ab.ca
Sat Mar 19 16:13:52 GMT 2022


The following packages have been upgraded in the Cygwin distribution:

* tzcode	2022a
* tzdata	2022a

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:

	https://mm.icann.org/pipermail/tz-announce/2022-March/000070.html


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. 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.

* 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.

* Fix bug when 32-bit time_t code reads malformed 64-bit TZif data.

* 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>.



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