Canada Debates Healthier Time: Standard or Daylight Savings?

The twice-yearly ritual of changing clocks may soon end, but a new question arises: which time should we keep? An analysis in the Canadian Medical Association Journal suggests permanent standard time is healthier. This debate is particularly relevant as several Canadian jurisdictions consider ending seasonal clock changes, prompting a deeper examination of the health implications of both options.

Researchers from the University of British Columbia, Simon Fraser University, and Vancouver Coastal Health compared health outcomes under permanent standard time and permanent daylight savings time. They found that morning light, essential for circadian rhythms, favors standard time. Daylight is one of the strongest signals regulating our body’s internal clock, and the researchers emphasize that exposure to light at the right times is key for maintaining these rhythms.

Health Evidence Points to Standard Time

The study highlights that morning light helps synchronize body clocks, while late-day light can disrupt them. Permanent daylight savings time would delay sunrise, forcing more people to wake and commute in darkness during winter. This could negatively impact sleep, mood, and safety, particularly for children, teenagers, and shift workers. The authors note that an estimated 1 percent to 3 percent of Canadians experience seasonal affective disorder, while as many as 15 percent experience milder seasonal changes in mood, sleep, appetite, and energy. Later winter sunrises could exacerbate these issues, especially for vulnerable populations.

Lead author Raymond W. Lam, a psychiatry professor, notes that major sleep and chronobiology organizations recommend permanent standard time. The analysis also references geographic research showing adverse health effects for those living farther west within a time zone, where sunrise occurs later. This research shows the importance of aligning local time with natural light patterns to minimize health risks.

Balancing Benefits and Drawbacks

Permanent daylight savings time provides more evening light, which can encourage exercise, socializing, and shopping. Yet, Patrick Baylis of the Vancouver School of Economics highlights trade-offs, including reduced sleep, lower productivity, and poorer educational outcomes. These negative effects could outweigh the benefits of extended evening daylight, particularly for students and workers.

Historical Precedents and Next Steps

History provides cautionary examples. The United States tried permanent daylight savings time in 1974 but returned to standard time within a year, amid opposition to dark winter mornings and concerns about children traveling to school before sunrise. Similarly, Russia and Chile abandoned permanent daylight savings time due to similar concerns. These historical precedents highlight the challenges of implementing permanent daylight savings time without addressing its drawbacks.