Time Zone Database Release 2026d Latest
Released
Downloads
| File | Description |
|---|---|
 tzdb-2026d.tar.lz (554.0kb) |
Complete Distribution (Data, Code and Extras) |
| tzdata2026d.tar.gz (468.2kb) |
Data Only Distribution |
| tzcode2026d.tar.gz (321.0kb) |
Code Only Distribution |
Release Notes
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.