[dependabot]

Bumps tzdata from 2025.2 to 2026.5.

Release notes

Sourced from tzdata's releases.

2026.5: Release of upstream tzdata 2026e

Version 2026.5

Upstream version 2026e released 2026-09-30T00:14:38+00:00.

Briefly:

Manitoba moves to permanent -05 on 2026-10-31.

Changes to future timestamps

Manitoba’s 2026-03-08 spring forward was its last foreseeable clock change, as it moved to permanent -05 thereafter. Model this with its traditional abbreviation EST. Although the change to permanent -05 legally takes place on 2026-10-31, 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.)

As the change affects both America/Winnipeg and its backward compatibility link, the obsolescent setting TZ="Canada/Central" will now use the abbreviation EST for affected timestamps, akin to TZ="Canada/Pacific" behavior introduced in 2026b.

Another TZDB release may be needed soon if any of the portions of northwestern Ontario historically aligned with America/Winnipeg do not follow. For now, given the short leadtime with Manitoba’s announcement, assume that they will, to avoid creating new zones that may not be needed if no divergence occurs.

Changes to past timestamps

In 1925 Ireland fell back on 09-20 not 10-04 (thanks to Stan Ulbrych).

Changes to commentary

Discussion on timekeeping practices in northwestern Ontario has been expanded in light of Manitoba’s recent announcement. It is not yet known whether or to what extent these areas may adapt their own timekeeping practices in response.

2026.4: Release of upstream tzdata 2026d

Version 2026.4

Upstream version 2026d released 2026-09-11T22:21:07+00:00

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

... (truncated)

Changelog

Sourced from tzdata's changelog.

Version 2026.5

Upstream version 2026e released 2026-09-30T00:14:38+00:00

Briefly:

Manitoba moves to permanent -05 on 2026-10-31.

Changes to future timestamps

Manitoba’s 2026-03-08 spring forward was its last foreseeable clock change, as it moved to permanent -05 thereafter. Model this with its traditional abbreviation EST. Although the change to permanent -05 legally takes place on 2026-10-31, 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.)

As the change affects both America/Winnipeg and its backward compatibility link, the obsolescent setting TZ="Canada/Central" will now use the abbreviation EST for affected timestamps, akin to TZ="Canada/Pacific" behavior introduced in 2026b.

Another TZDB release may be needed soon if any of the portions of northwestern Ontario historically aligned with America/Winnipeg do not follow. For now, given the short leadtime with Manitoba’s announcement, assume that they will, to avoid creating new zones that may not be needed if no divergence occurs.

Changes to past timestamps

In 1925 Ireland fell back on 09-20 not 10-04 (thanks to Stan Ulbrych).

Changes to commentary

Discussion on timekeeping practices in northwestern Ontario has been expanded in light of Manitoba’s recent announcement. It is not yet known whether or to what extent these areas may adapt their own timekeeping practices in response.

---

Version 2026.4

Upstream version 2026d released 2026-09-11T22:21:07+00:00

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

... (truncated)

Commits

• 9493aab Update tzdata to version 2026e (#154)
• b4d2086 Update tzdata to version 2026d (#153)
• 91a9022 Switch keyserver used for tarball GPG verification (#152)
• c97164f Bump the actions group with 3 updates (#150)
• 6c7fa78 Stop testing 3.8 and 3.9, test 3.15 and PyPy3 (#148)
• d165386 Bump the Actions group with 2 updates (#149)
• a442794 Update tzdata to version 2026c (#145)
• 8f35937 Use the release environment for TestPyPI publishes (#146)
• ba0b891 Few fixes to the maintaining doc
• 9a7e6a0 Add Stan Ulbrych to license
• Additional commits viewable in compare view