Canadian Analysis Finds Permanent Standard Time Fits the Body Clock Better Than Permanent Daylight Saving Time
In early January, the sun doesn’t rise until after 7:30 a.m. in cities from Vancouver to Halifax. Kids head to school under streetlights, and drivers scrape ice off windshields in the dark. A new analysis warns that permanent daylight saving time, the option several Canadian regions have already adopted, would push sunrise past 8:30 a.m., every winter, for good.
That’s the tradeoff at the heart of a new paper in the Canadian Medical Association Journal. Several Canadian regions are weighing which time to lock in once the twice-yearly clock change ends, and North American governments that have acted have largely picked permanent daylight saving time. A group of Canadian physicians and researchers reviewed the available evidence and reached the opposite conclusion: permanent standard time is the healthier choice.
Yukon switched to permanent daylight saving time in 2020. British Columbia followed in March 2026, and Alberta and the Northwest Territories did the same a month later. In July 2026, the U.S. House of Representatives passed a bill making daylight saving time permanent nationwide, and it now sits before the Senate. Major sleep and body-clock research societies have all called for permanent standard time instead.
Permanent Daylight Saving Time Delays the Morning Light the Body Clock Needs
Human bodies run on an internal clock slightly longer than 24 hours, so daylight has to reset it every day. Morning light nudges the clock earlier, which helps people wake on schedule, and evening light pushes it later. Many people spend much of the day indoors, away from bright morning light, while electric lighting and screens stretch exposure into the night. The result can be “social jet lag,” a mismatch between the body’s natural schedule and the schedule that work or school demands. Studies tie it to poor sleep and worse mental health.
Permanent daylight saving time worsens that pattern in winter by prolonging morning darkness. Permanent standard time keeps winter sunrises earlier, though it brings earlier sunsets and earlier summer dawns that may wake some people too early.
Evidence Favors Permanent Standard Time for Sleep, Mood, and School Performance
No volunteers took part, so there is no sample size. Four authors, spanning psychiatry, psychology, and economics, reviewed existing studies to compare the two options.
In U.S. county-level analyses, people on the western edge of a time zone, where the sun rises later by the clock, averaged as many as 2 additional suicide deaths per 100,000 people each year compared with those on the eastern edge, a gap that mimics the later sunrises permanent daylight saving time would bring. Limited evidence also links living farther west to higher rates of seasonal affective disorder, the clinical term for winter depression, which an estimated 1% to 3% of people in Canada live with.
A 2025 computer simulation found that both permanent options beat clock changes for health, but permanent daylight saving time’s benefits were a third lower than permanent standard time’s. One analysis of U.S. time zones found that an hour of later sunset cut weekly sleep by nearly an hour and long-term earnings by about 5%. In Florida, an extra hour of sunlight before school was linked to higher math and reading scores among teens. Later dusk has perks, but the paper says the downsides for sleep, productivity, and learning are better established.
Source : https://studyfinds.com/permanent-standard-time-beats-daylight-saving-time/
