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Supabase showing the wrong local time? Vancouver, Edmonton and Casablanca fix

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Source checked 31 Oct 2026 · Published 31 Oct 2026 · Last reviewed 31 Oct 2026 · By Ctrl+Z Therapy (how we test)

The short answer

Supabase's changelog of October 30, 2026 and its troubleshooting guide say some older Supabase Postgres versions ship an outdated tzdata package. Local-time conversions such as AT TIME ZONE 'America/Vancouver' then return incorrect results for three zones whose rules change in 2026: British Columbia (America/Vancouver) on March 8, Morocco (Africa/Casablanca) on September 20, and Alberta (America/Edmonton) on November 1. Your stored data is not affected, and timestamps stay intact; only the conversion to local time for these zones is wrong.

What to do

  1. Check Service Version under Project Settings, General. Versions earlier than 15.19.0.003 (Postgres 15) or 17.11.0.003 (Postgres 17) are affected if you use one of these zones.
  2. Upgrade the project from the same page. The upgrade causes downtime, so plan it for a low-traffic window.
  3. Then rebuild only the indexes whose definition converts to one of these zones. Indexes on plain timestamp columns are not affected.
  4. Ask your AI tool: "Check whether this Supabase project converts times to America/Vancouver, America/Edmonton or Africa/Casablanca. If it does, list every index that uses AT TIME ZONE, so I can rebuild them after upgrading the project."

Good to know

  • No error is raised when this happens.

Source

Checked on 31 Oct 2026. Prices, limits and settings change, so check the source before you rely on them.