Hi all, Quick update on this — the PR has been merged:
https://github.com/apache/cloudberry/pull/1674 The bundled timezone data on REL_2_STABLE is now updated to tzdata 2025b. This includes the fix for America/Mexico_City (Mexico DST abolishment) along with all other upstream timezone changes through 2025b. The issue has been closed: https://github.com/apache/cloudberry/issues/1670 Thanks to everyone who reviewed! Best regards, Max Yang On Fri, Apr 10, 2026 at 10:17 AM Max Yang <[email protected]> wrote: > Hi all, > > I'd like to bring up a timezone data issue that was recently reported > by a community user and share what we've found so far. > > A user in Mexico reported a 1-hour time discrepancy between the OS > and the database when using the America/Mexico_City timezone. After > investigation, we identified the root cause: > > 1. Mexico abolished Daylight Saving Time in October 2022 > > Mexico officially stopped observing DST, so America/Mexico_City > should now stay on CST (UTC-6) year-round. However, the database > still switches to CDT (UTC-5) every April, causing the 1-hour > discrepancy the user reported. > > 2. Cloudberry's bundled tzdata is outdated > > Cloudberry is based on PostgreSQL 14.4 (circa 2022), which ships > with tzdata 2022a (released March 2022) — before Mexico's DST > abolishment was enacted. The fix was included in tzdata 2022f > (released October 2022), but Cloudberry never picked it up. > > 3. PostgreSQL upstream has long since fixed this > > Upstream PostgreSQL updated the bundled tzdata multiple times since > then, with the latest being 2025b. The key change was modifying > the Mexico DST rule from "2002 to max" to "2002 to 2022", so that > DST is no longer applied after 2022. > > I have verified that the upstream tzdata updates (2022f through > 2025b) can be cleanly cherry-picked onto the REL_2_STABLE branch. > A draft PR is available at: > > https://github.com/apache/cloudberry/pull/1674 > > The changes are limited to timezone data files only — no code logic > is involved. Besides the Mexico fix, these updates also include DST > law changes for Greenland and Chile, new timezones like > America/Ciudad_Juarez and America/Coyhaique, and historical > corrections for multiple regions. > > We don't need to apply this to main separately, as it will be > covered by the upcoming PostgreSQL 16.x merge. > > The original issue is tracked at: > > https://github.com/apache/cloudberry/issues/1670 > > Any feedback or concerns are welcome. Thanks! > > Best regards, Max Yang >
