With two provinces ending DST, studies shows pros and cons of making change in various countries
Alberta’s move to scrap twice‑yearly clock changes and keep daylight time year‑round would put the province on the same path as several countries that have already abandoned daylight saving time (DST) adjustments – with mixed results for health, safety and daily life, according to previous studies.
Premier Danielle Smith’s government confirmed this week that Alberta intends to end seasonal time changes and remain on a single time permanently, effectively adopting year‑round Mountain Daylight Time if legislation passes.
Officials have argued the change would simplify life for residents and businesses and align the province more closely with British Columbia and Yukon, which are also moving to fixed daylight time regimes.
British Columbia also announced it was changing its clocks for the last time on March 8, 2026, when the province moved to permanent daylight saving time and adopted a new year-round “Pacific time” zone.
International evidence suggests that while eliminating the clock change itself can reduce short‑term health and safety risks, the choice to lock in permanent daylight time – rather than permanent standard time – carries clear trade‑offs.
Health and safety: gains from ending the switch
Research in Europe and North America links the spring transition into DST to a measurable rise in heart attacks, strokes and traffic collisions in the weeks that follow. Studies point to disrupted sleep and abrupt shifts in circadian rhythms as key factors, particularly for people with existing cardiovascular conditions and those working early shifts.
Large observational studies and reviews in North America and Europe point to the same pattern: the spring transition to DST briefly but measurably raises cardiovascular and safety risks.
|
Outcome |
Key study / review |
Reported impact of spring DST change |
|
Heart attacks (AMI) |
Janszky et al., Swedish myocardial infarction registry; discussed in later reviews and health‑impact summaries |
Up to about 5% more heart attacks in the first three weekdays after the spring shift, with the largest increases seen immediately after the transition |
|
Stroke (overall) |
Finnish ischaemic stroke analysis (University of Turku / Kuopio group) |
Around 8% higher ischaemic‑stroke rate in the first two days after the spring clock change |
|
Stroke in vulnerable patients |
Same Finnish ischaemic stroke study |
Approximately 25% higher stroke risk after the change among people with cancer |
|
Long‑term stroke & obesity |
Zeitzer & Weed, “Circadian‑informed modeling predicts regional variation in obesity and stroke outcomes under different permanent US time policies,” PNAS 2025 (Stanford‑linked modelling) |
Abolishing clock changes could prevent >300,000 strokes and >2 million obesity cases a year in a U.S.‑sized population, with permanent standard time performing best |
|
Fatal traffic collisions |
Fritz et al., “A Chronobiological Evaluation of the Acute Effects of Daylight Saving Time on Traffic Accident Risk,” Current Biology 2020; widely cited in DST reviews |
About a 6% increase in fatal crashes in the workweek after the spring DST transition, concentrated in morning hours and in western parts of time zones |
|
Workplace injuries |
Barnes & Wagner, “Changing to daylight saving time cuts into sleep and increases workplace injuries,” Journal of Applied Psychology 2009 |
On the Monday after spring DST, U.S. mining workers experienced ~6% more injuries and nearly 70% more lost workdays than on other Mondays |
A 2025 Stanford‑led study modelled how three regimes – permanent standard time, permanent daylight time and the current biannual switch – would affect health across the continental United States.
Using county‑level light‑exposure data and disease statistics, researchers concluded that moving to a single year‑round time would reduce “circadian burden” compared with switching, and that permanent standard time would deliver the largest benefits, preventing an estimated 300,000 strokes and 2.6 million cases of obesity annually.
Doing away with DST could bring many positives to workers’ health, according to a previous report.
Darker mornings, social pushback
Here’s the impact of eliminating the switching of hours, based on the experiences of these countries:
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Russia abolished seasonal clock changes in 2011 and shifted to permanent “summer time,” placing clocks one hour ahead of standard time all year. The move led to very late winter sunrises in many regions, with reports of children travelling to school in darkness and widespread complaints about fatigue and mood. In 2014, after sustained public dissatisfaction, Russia reversed course and adopted permanent standard time instead, while still keeping seasonal changes off the books.
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Turkey ended seasonal clock changes in 2016 and has remained on UTC+3 year‑round, a policy that effectively locks in permanent daylight time. The government argued the shift would save energy and extend evening light, but subsequent analyses of electricity‑market data suggest net energy savings have been limited, as higher demand in darker winter mornings offsets some reductions later in the day. Public debate has focused on the burden of starting work and school in darkness, especially in western parts of the country.
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Morocco adopted GMT+1 as its year‑round time in 2018, with a temporary reversion to GMT during Ramadan. Authorities said the change would cut power use and align the country more closely with European business hours. Since then, more than 300,000 people have signed petitions calling for an end to permanent GMT+1, citing sleep disruption, constant tiredness, stress and safety concerns for children on dark morning commutes. Analysts have questioned whether the modest projected energy gains justify the reported health and social costs.
Taken together, the three cases show that while ending clock changes removes transition‑related risks, permanent daylight time at higher latitudes can trigger sustained backlash if winter sunrises move too far into the morning.
In 2025, Liberal MP Marie-France Lalonde said she will introduce legislation that could possibly put an end to the annual shifting of hours.
