Canadian medical experts urge permanent standard time over daylight saving time

Canadian medical specialists are calling for a definitive shift toward permanent standard time rather than permanent daylight saving time as several Canadian jurisdictions move to eliminate the twice-yearly clock change.

While many regions across Canada explore ending the seasonal time switches, a new analysis published in the Canadian Medical Association Journal highlights that abandoning the biannual adjustment leaves a crucial secondary choice open regarding which time regime to maintain year-round, according to reporting by Miragenews. Both options present distinct advantages and drawbacks. Permanent daylight saving time extends evening light to support recreation, commuting, and social activities, but it simultaneously forces winter sunrises an hour later into the morning.

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"Ending the clock change solves one problem, but it creates another decision: which time should we live on year-round?" says lead author Dr. Raymond Lam, professor of psychiatry at the University of British Columbia (UBC), Vancouver, BC. "The health evidence points to standard time, largely because morning light matters for our body clocks, sleep, and mood."

Dr. Raymond Lam, lead author and professor of psychiatry at the University of British Columbia, Vancouver, BC, via Miragenews

Major sleep and chronobiology organizations emphasize that biological clocks rely heavily on morning light to maintain synchronization with a 24-hour day, whereas evening light delays circadian rhythms. Dr. Ralph Mistlberger, professor of psychology at Simon Fraser University, Vancouver, BC, noted via Miragenews that permanent daylight saving time shifts vital natural light later precisely when winter mornings are at their darkest.

Health impacts of these choices span multiple demographics. Between 1% and 3% of people in Canada experience seasonal affective disorder, while up to 15% suffer milder seasonal fluctuations in mood, energy, appetite, and sleep. Geographic studies cited in the analysis indicate that individuals living farther west within a time zone—where the clock registers later sunrises—face increased adverse health outcomes. Children, adolescents, shift workers, early-start employees, public transit users, pedestrians, cyclists, and residents in lower-income or rural communities with inferior infrastructure are particularly vulnerable.

Proponents of permanent daylight saving time point to the appeal of longer evening hours for exercise, shopping, and socializing after work and school. Dr. Patrick Baylis, associate professor at the Vancouver School of Economics at UBC, acknowledged these popular evening benefits but stressed they must be weighed against evidence linking later solar time to reduced sleep, diminished productivity, and poorer educational outcomes, according to Miragenews.

"The attraction of permanent daylight saving time is easy to understand. People like more light after work and school," says Dr. Patrick Baylis, associate professor at the Vancouver School of Economics at UBC. "But those evening benefits have to be weighed against evidence linking later solar time with less sleep, lower productivity, and worse educational outcomes."

Dr. Patrick Baylis, associate professor at the Vancouver School of Economics at UBC, via Miragenews

Historical precedents offer cautionary lessons from abroad. The United States enacted permanent daylight saving time during the 1974 energy crisis but repealed it within a year due to public backlash over dark winter mornings and safety worries for children traveling to school before sunrise. Russia adopted permanent daylight saving time in 2011 before reversing the policy in 2014, and Chile similarly abandoned a nationwide experiment with permanent daylight saving time following its 2015 trial.

The analysis authors recommend that if governments nevertheless pursue permanent daylight saving time, they must proactively implement mitigating measures before winter arrives. Such strategies include upgrading pedestrian and road safety infrastructure, introducing flexible or delayed school and work start times, boosting indoor morning light exposure, and closely tracking sleep patterns, mental health metrics, and injury rates. Conversely, permanent standard time demands fewer interventions, primarily centering on managing earlier winter evenings and earlier summer dawns.

Dr. Alexandra Choi, a medical health officer with Vancouver Coastal Health, noted via Miragenews that time policy functions as public health policy and that if governments choose permanent daylight saving time, they should plan for the consequences before the first winter.

The authors conclude that the preponderance of health evidence favours permanent standard time. As Dr. Lam stated in the reporting from Miragenews, attention must now turn to what happens the morning after the clocks stop changing.