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Diffstat (limited to 'NEWS')
| -rw-r--r-- | NEWS | 115 |
1 files changed, 114 insertions, 1 deletions
@@ -1,5 +1,87 @@ News for the tz database +Release 2026d - 2026-09-11 15:21:07 -0700 + + Briefly: + Canada’s Northwest Territories moved to permanent -06 on 2026-08-21. + Obsolescent settings like TZ="EST5EDT" now conform better to POSIX. + Fix security, performance and porting bugs in zic and localtime. + + Changes to future timestamps + + Canada’s Northwest Territories will not fall back on 2026-11-01 + and will stay on -06 year-round, matching Alberta’s recent change. + Model this with its traditional abbreviation CST. Although the + change to permanent -06 legally took place on 2026-08-21, + temporarily model the change to occur on 2026-11-01 at 02:00 + for the same reason as other recent temporary hacks. (Caution: + see “NOTE FOR 2026b TEMPORARY HACK FOR CLDR AND CANADA” below.) + This affects only America/Inuvik as the rest of the territory is + covered by America/Edmonton, for which the equivalent change was + released in 2026c. + + Changes to past timestamps + + Colombia’s 1992-05-02 spring forward was at 00:00, not 24:00. + + Iran’s 1979-05-26 spring forward was at 00:00, not 24:00. + (Thanks to N.F. Hase.) + + The backward-compatibility names EST5EDT, CST6CDT, MST7MDT, and + PST8PDT now conform better to POSIX. For example, EST5EDT now + always uses the abbreviation "EST" for standard time (now always 5 + hours behind UT) and "EDT" for daylight saving time, whereas it + formerly had different UT offsets before standard time was + introduced and sometimes used abbreviations like "LMT", "EWT" and + "EPT", all contrary to POSIX. Also, though not required by POSIX + these names now use US federal rules rather than rules of places + like New York, reverting to 2024a behavior. This change affects + only timestamps before 1966-10-30 at 01:00 standard time. + + Other data changes + + The temporary hacks used for North American timekeeping changes + now work around a libstdc++ std::chrono bug in GCC 14.1-14.4, + 15.1-15.2, and 16.1; see GCC bug 124851. This data change does + not affect TZif files or timestamps. The change does not work + around the related but less serious GCC bugs 116110 and 124513. + These GCC bugs are all fixed in GCC 16.2. + + Changes to code + + zic now rejects Link targets that would have invalid names, and + more efficiently processes Expires, Leap and Rule lines with years + far in the past or future. (Thanks to Darren Carreras.) + + zic now ports to systems that report lack of link support via + EINVAL, ENOSYS or EPERM errno values. (Thanks to Tom Lane.) + + When tzset and related functions encounter a TZif file that is too + large for them, they now consistently fail instead of sometimes + silently ignoring excess parts of the file. + + localtime-related functions no longer mishandle extreme timestamps + when given TZif files holding some unlikely timezone histories. + (Problem reported by David Sarkisyan.) + + localtime-related functions no longer check the values of TZif + files’ standard/wall and UT/local indicators, which these + functions have not used since 2026a’s removal of the old + posixrules feature. + + tzcode has been ported to Haiku. + + localtime.c now works again by default on AIX and DragonFly BSD. + + zic now rejects ‘:’ and ‘\’ in Zone and Link names when running on + Microsoft Windows. (Problem reported by David Diaz.) + + Changes to documentation + + URLs for release tarballs in tz-link.html have been updated to + reflect their new canonical URLs on data.iana.org. + + Release 2026c - 2026-07-08 10:23:58 -0700 Briefly: @@ -15,7 +97,13 @@ Release 2026c - 2026-07-08 10:23:58 -0700 CST. Although the change to permanent -06 legally took place on 2026-06-18, temporarily model the change to occur on 2026-11-01 at 02:00 instead, for the same reason we introduced a similarly - temporary hack for British Columbia in 2026b. + temporary hack for British Columbia in 2026b. (Caution: see + “NOTE FOR 2026b TEMPORARY HACK FOR CLDR AND CANADA” below.) + + As the change affects both America/Edmonton and its backward + compatibility link, the obsolescent setting TZ="Canada/Mountain" + will now use the abbreviation CST for affected timestamps, + akin to TZ="Canada/Pacific" behavior introduced in 2026b. Although another TZDB release will likely be needed soon because Northwest Territories will likely follow Alberta, the legal @@ -67,6 +155,7 @@ Release 2026b - 2026-04-22 23:06:43 -0700 Briefly: British Columbia moved to permanent -07 on 2026-03-09. + zic no longer mishandles a last transition to a new time type. Some more overflow bugs have been fixed in zic. Changes to future timestamps @@ -79,9 +168,33 @@ Release 2026b - 2026-04-22 23:06:43 -0700 limitation in CLDR 48.1 (2026-01-08). This temporary hack is planned to be removed after CLDR is fixed. + To match longstanding practice for -07 standard time in North + America, such as for America/Dawson, America/Dawson_Creek, + America/Fort_Nelson and America/Whitehorse, affected BC + timestamps use the abbreviation MST. As the change affects both + America/Vancouver and its backward compatibility link, the + obsolescent setting TZ="Canada/Pacific" will now use the + abbreviation MST. Future TZDB releases may change the + abbreviation if something else becomes popular across areas + observing -07, and may change it to "-07" if no alphabetic + consensus emerges. + Changes to code zic no longer mishandles a last transition to a new time type. + NOTE FOR 2026b TEMPORARY HACK FOR CLDR AND CANADA: + This zic fix is needed for the temporary hack (mentioned above) + that works around the Canadian timekeeping bug in Unicode CLDR. + Without the fix, the temporary hack causes zic versions 2023d + through 2026a, in their default mode that generates slim output, + to generate a TZif file that violates Internet RFC 9636 §3.3. + The buggy file in turn causes some TZif readers, including tzcode + itself, to ignore America/Vancouver’s 2026-11-01 02:00 transition + from PDT (tm_isdst=1) to MST (tm_isdst=0). Although the buggy + file does not cause any known TZif reader to mishandle UT offsets, + caution is advised when using zic 2023d through 2026a to compile + data from more-recent tz releases. To work around this problem + when using these older zic versions, use ‘zic -b fat’. zic no longer overflows a buffer when generating a TZ string like "PST-167:59:58PDT-167:59:59,M11.5.6/-167:59:59,M12.5.6/-167:59:59", |