Alberta stopped changing its clocks in June. 19 of 19 frontier models still put Calgary on standard time in November.

Description and use

Models incorrectly answered the Toronto time for 9 a.m. Calgary on 15 Nov 2026 after Alberta stopped daylight saving. The correct answer is 10 a.m.

Problem

Determine the correct local time in Toronto when it is 9 a.m. on November 15 in Calgary after Alberta ceased daylight‑saving time in 2026.

Outcome

All 19 models answered incorrectly, giving 11:00 instead of the correct 10:00. The benchmark demonstrates that models lack up‑to‑date knowledge of recent time‑zone changes.

Workflow

• 1. Identify the date and location: 9 a.m. on 15 Nov 2026 in Calgary.
• 2. Consult the IANA tzdata 2026d release to get Calgary’s UTC offset (‑06:00).
• 3. Convert 9 a.m. Calgary time to UTC: 3 p.m. UTC.
• 4. Apply Toronto’s UTC offset (‑05:00) to UTC time: 10 a.m. Toronto time.
• 5. Verify with Python’s zoneinfo or a reliable time‑zone API.
• 6. Record the answer as 10:00.
• 7. Compare model outputs to the correct answer to assess accuracy.

Evidence

All 19 said 11:00. The answer is 10:00.

Source

The Calgary offset question is the one I would put in front of a judge, because it cannot be right by accident. Calgary at noon on November 15, 2026 is -06:00. All 19 models said -07:00.

Source