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Permanent Daylight Time May Be the Wrong Call, Scientists Say
More Canadian provinces are ditching the clock change, but researchers say choosing permanent daylight time over standard time could hurt your health.
Canada's time-change divide widened this weekend as millions of Canadians turned their clocks back on November 1 — while millions of others didn't bother, because their province no longer does. The split is drawing fresh scrutiny from sleep and circadian rhythm researchers who say several provinces made the wrong call about which time to keep.
British Columbia, Alberta, Manitoba, and the Northwest Territories have all stopped changing their clocks twice a year, joining Yukon and Saskatchewan in staying on a fixed time year-round. Ontario, Quebec, and the Atlantic provinces still observe the fall-back. Quebec, though, may be on its way out: Premier Paul St-Pierre Plamondon announced Wednesday that the province will end the twice-yearly change, with a final decision on which time to keep coming after expert consultations.
What the science says about standard vs. daylight time
The choice between permanent standard time and permanent daylight time isn't just a scheduling preference — it has measurable effects on health. Research points toward standard time (the "fall back" time we return to each autumn) as the option that better aligns with the body's natural rhythms.
Joseph De Koninck, an emeritus professor of psychology at the University of Ottawa who has studied sleep for decades, explains that the body's internal clock relies on light to stay calibrated. Gradual seasonal shifts are manageable. A sudden one-hour jump is harder on the body — particularly the spring-forward change, which costs people an hour of sleep overnight.
"We are able to adapt, but it's not optimal for our health," De Koninck said.
Alberta's late sunrises are about to get later
For Alberta specifically, the concern is concrete. Michael Antle, head of the psychology department at the University of Calgary and a researcher focused on circadian rhythms, says permanent daylight time was the wrong choice for the province.
Alberta's northern latitude and its position within its time zone already push winter sunrises late in the morning. Under permanent daylight time, those sunrises shift another hour forward — meaning Edmonton could see winter sunrises as late as 10 a.m.
"It's not the choice I would have made," Antle said of Alberta's decision.
Morning light plays a critical role in keeping people's internal clocks on track. Most people's circadian rhythms naturally run a little slow, making them mildly "night owlish." Exposure to early morning light speeds that clock up and helps people feel alert earlier. Push sunrise back an hour, and you widen the gap between what the body wants to do and what work or school demands.
What this means for Canadians
The provinces that have already locked in permanent daylight time — BC, Alberta, Manitoba — are unlikely to reverse course anytime soon. But Quebec's deliberate, expert-led approach offers a model: consult the science before committing.
For Canadians in provinces still observing the twice-yearly change, the debate is a reminder that "ending the time change" is only half the decision. The half that follows — which time you keep — may matter just as much to your sleep, your mood, and your long-term health.