Overview
- A University of British Columbia review published in CMAJ recommends that if seasonal clock changes end, governments should choose permanent standard (winter) time to protect circadian health.
- The review says natural morning light is key to synchronizing the human circadian clock and that later evening light under permanent summer time would delay sleep timing and worsen sleep, mood, and performance.
- Researchers and sleep societies cite studies showing short‑term rises in heart attacks, rhythm disorders and accident risk after the spring clock shift, with people who have heart disease and night‑type sleepers most affected.
- The Canadian province of British Columbia has already ended the semi‑annual change and will stay on UTC−7 year‑round, while the European Union has not agreed a common policy and will continue seasonal switching, with Germany returning to winter time on the night of Oct. 24–25, 2026.
- Past national experiments with year‑round summer time were reversed because darker winter mornings harmed children and public acceptance, so policymakers face trade‑offs over safety, schooling, work schedules and cross‑border coordination.