Winter time or summer time? What the science says about the best option for health

Winter Time or Summer Time: Which Is Better for Health?

Poinews.com – The debate over winter time or summer time returns whenever clocks change. In many countries, moving clocks back by one hour brings earlier daylight in the morning and darker evenings. Scientists broadly agree that ending the twice-yearly clock change could reduce disruption to sleep, but research suggests the choice of permanent time matters greatly for health.

Winter time, also called standard time, is more closely aligned with the sun’s natural schedule. That means earlier sunrise in the colder, darker months, when many people are travelling to school or work before daylight. Permanent summer time, or daylight saving time, would preserve brighter evenings but shift morning light an hour later.

Why morning daylight matters

Light is one of the strongest signals for the body’s circadian rhythm, the internal system that helps regulate sleep, alertness and other daily functions. Exposure to daylight early in the day helps keep this clock synchronised with the 24-hour cycle.

A recent analysis led by Raymond Lam, professor of psychiatry at the University of British Columbia, concluded that permanent standard time is the healthier option. The researchers argued that it better matches biological timing because it provides more useful morning light, particularly during winter.

“Ending the clock change solves one problem, but it creates another decision: which time should we live on year-round?”

Ralph Mistlberger, a psychology professor at Simon Fraser University in Canada, has also highlighted the importance of morning light. When dawn arrives later, people may wake, commute, work or attend school in darkness more often. This can make it harder for the body clock to stay aligned with the daily schedule.

“Our biological clocks need morning light to stay synchronized with the 24-hour day. Permanent daylight saving time moves that light an hour later just when winter mornings are already darkest.”

The health impact of changing clocks

The spring and autumn clock changes can interrupt routines and sleep patterns. The spring transition is often particularly difficult because people lose an hour of sleep. Removing those seasonal changes could avoid the repeated adjustment and the short-term effects of disrupted sleep.

However, ending clock changes does not automatically settle the wider public-health question. A permanent summer-time system would avoid the transitions but would also delay sunrise throughout the year. In winter, that could leave more people beginning their day before daylight appears.

Supporters of permanent daylight saving time often point to lighter evenings. Extra evening daylight can make outdoor activity, social plans, after-work travel and family time more appealing. These benefits are real lifestyle considerations, especially for people with conventional work or school schedules.

But the science behind winter time or summer time suggests that morning daylight has a distinct biological value. Earlier exposure to natural light may support alertness, sleep quality and mood by helping the circadian rhythm remain on schedule.

Standard Time and Daily Life

Seasonal clock changes were first introduced during the First World War as an energy-saving measure, and many countries brought them back during the 1970s. Today, the discussion is less focused on energy use and more concerned with sleep, safety, work patterns and public health.

The effects of a permanent time system would vary by location. Places with long, dark winters would experience the delayed sunrise under permanent summer time more sharply than areas closer to the equator. Work hours, school start times and commuting patterns would also influence how communities experience any change.

Alexandra Choi, a medical health officer with Vancouver Coastal Health, has said that governments should treat time policy as a public-health matter. If authorities choose permanent daylight saving time, she argues they should plan for its consequences rather than viewing it only as a preference for lighter evenings.

“Time policy is a public health policy.”

The evidence does not suggest that evening daylight has no value. Instead, it indicates that policy makers should weigh those benefits against the need for morning light, especially during the darkest months. For health researchers, permanent standard time offers the closer fit with the body’s natural rhythm.

FAQ: Winter Time or Summer Time

Is winter time the same as standard time?

Yes. Winter time generally refers to standard time, the clock setting used after daylight saving time ends. It places sunrise and sunset earlier than summer time.

Why do scientists often favour permanent standard time?

Researchers point to earlier morning daylight, which helps regulate the circadian rhythm. This alignment may support sleep, alertness and mood, particularly during winter.

Would permanent summer time mean lighter evenings?

Yes. Keeping daylight saving time all year would provide more evening light, but sunrise would also occur an hour later than under permanent standard time.

What can people do when clocks change?

Keeping a regular sleep routine, getting daylight early in the day and avoiding major schedule changes can help make the transition easier. People who are especially sensitive to sleep disruption may benefit from adjusting bedtime gradually in the days before a clock change.