Time Zone Database Release 2026c Latest
Released
Downloads
| File | Description |
|---|---|
 tzdb-2026c.tar.lz (550.0kb) |
Complete Distribution (Data, Code and Extras) |
| tzdata2026c.tar.gz (464.5kb) |
Data Only Distribution |
| tzcode2026c.tar.gz (317.8kb) |
Code Only Distribution |
Release Notes
Briefly:
Alberta moved to permanent -06 on 2026-06-18.
Morocco moves to permanent +00 on 2026-09-20.
More integer overflow bugs have been fixed in zic.
Changes to future timestamps
Alberta’s 2026-03-08 spring forward was its last foreseeable clock
change, as it moved to permanent -06 thereafter. (Thanks to Roozbeh
Pournader and others.) Model this with its traditional abbreviation
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.
Although another TZDB release will likely be needed soon because
Northwest Territories will likely follow Alberta, the legal
formalities have not yet taken place.
Morocco plans to move back to permanent UTC, without daylight
saving time transitions, on 2026-09-20 at 02:00. This also
affects Western Sahara.
Changes to code
zic no longer overflows integers when processing outlandish input
like ‘Zone Ouch 0 - LMT 9223372036854775807’, ‘Zone Ouch 0
2562047788015215 LMT’, ‘Zone Ouch -2562047788015215:30:08 - LMT’,
and ‘Zone Ouch -2562047788015215:30:08 - %%z’. This avoids
undefined behavior in C. (Problems reported by Naveed Khan.)
On platforms that have EFTYPE, tzalloc now fails with errno set to
EFTYPE, not EINVAL, if it detects that the TZif file has an
invalid format or is not a regular file. Formerly it did this
only on NetBSD, and only when the file was not a regular file.
Unprivileged programs no longer require TZif files to be regular
files or reject relative names containing ".." components. This
reverts to the more-permissive 2025b behavior, as the stricter
behavior did not catch on in FreeBSD.
zic now reports any failure to remove a temporary file when
cleaning up after a previous failure. (Problem reported by Tom
Lane.)
Changes to commentary
Northwest Territories is expected to move to permanent -06 prior to
2026-11-01 02:00, when clocks would otherwise fall back. (Thanks to
Tim Parenti and James Bellaire.) Model this with its traditional
abbreviation CST. Unfortunately the change is not yet official, so
it is currently present only as comments that can be uncommented as
needed.
Changes to build procedure
The undocumented ‘typecheck’ Makefile check rule has been removed.
It stopped working in 2025a and evidently nobody noticed.
The rule was superseded by ‘check_time_t_alternatives’ in 2013d.