10/17/2026
⏰ If countries stop changing their clocks twice a year, which time should they keep? A new Canadian analysis says permanent standard time is the healthier choice.
Many places are debating an end to clock changes. British Columbia, Alberta and the Northwest Territories have chosen year-round daylight saving time, and the US House voted for it in July.
Researchers led by psychiatrist Raymond Lam of the University of British Columbia reviewed studies on sleep, body clocks, mood, school and the economy.
Their conclusion: if clocks stop changing, standard time is better for health.
The key reason is morning light. Light early in the day helps keep our internal body clock in sync.
Under permanent daylight saving time, winter mornings stay dark much longer. In Toronto, the latest winter sunrise would be 8:51 am instead of 7:51 am.
With less morning light, the body clock can drift later. But school and work still start at the same time.
That can mean shorter sleep and more "social jetlag," which has been linked to poorer physical and mental health. Teens and young adults may be most affected.
Darker winter mornings could also worsen seasonal depression in some people.
Permanent daylight saving time does have upsides. Lighter evenings make outdoor activity easier.
History offers lessons too. The US tried year-round daylight saving time in 1974 and dropped it within a year. Russia adopted it in 2011 and reversed course in 2014.
There are caveats. This is a review, and much of the evidence comes from observational studies, which show links rather than cause and effect.
The long-term health effects of permanent time policies are still uncertain, and how much they matter depends on where you live.
📃 RESEARCH PAPER
📌 Raymond W. Lam et al., "Analysis of health impacts associated with adopting permanent standard time or permanent daylight saving time to inform policy in Canada," Canadian Medical Association Journal (2026).