The following test packages have been uploaded to the Cygwin distribution: * tzdata 2024a-2 * tzdata-right 2024a-2 * tzdata-posix 2024a-2 This Cygwin test release splits out the likely rarely used "right" and "posix" subtrees from mandatory base /usr/share/zoneinfo into their own optional packages tzdata-right and tzdata-posix. Tests checking for missing or invalid representative zones in all parts of the base, posix, and right subtrees has been added as part of the package definition script. Please test this base package and report any issues, and let us know if you need to install and use the zones in the "right" or "posix" subtrees in the optional tzdata-right and tzdata-posix packages, and whether this change causes any issues for you. If there are no reports of issues, all future tzdata updates will be split into three packages, and only the base tzdata package installed by default on all systems. The space occupied by installed files, and downloaded from mirrors, is shown below for each package, plus the current package with all zones. install tar tzdata 721KB 172KB base 984KB 78KB right 669KB 74KB posix 1367KB 444KB source 3667KB 452KB current 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 summer daylight saving time rules, UTC offsets, and time zone boundaries. Three data packages are available: base 'tzdata' is always installed; optional 'tzdata-right' provides TAI-10s time in the 'right' subtree; and optional 'tzdata-posix' provides the same zones and times as base data in the 'posix' subtree, as an explicit distinction from 'right'. The tzcode package provides the tzselect, zdump, and zic utilities. For more information, see the project home page: https://www.iana.org/time-zones For more details on changes, see the announcement or below: https://mm.icann.org/pipermail/tz-announce/2024-February/000081.html 2024a 2024-02-01 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. - Palestine springs forward a week later than previously predicted in 2024 and 2025. 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. - From 1947 through 1949, Toronto's transitions occurred at 02:00 not 00:00. - 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. - 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. - strftime %s now uses tm_gmtoff if available. 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. Changes to documentation - The strftime man page documents which struct tm members affect which conversion specs, and that tzset is called.