Updated: tzcode, tzdata 2022a
Cygwin tzcode/tzdata Maintainer
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:
Release 2022a - 2022-03-15 23:02:01 -0700
* 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
* 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,
More information about the Cygwin-announce