Scientists explained why countries choose permanent winter time

Canadian scientists have established that after the abolition of seasonal clock changes, people should live year-round on standard winter time. The results of the study, published in the Canadian Medical Association Journal, indicate that this schedule most accurately aligns with the human body's biorhythms and helps avoid serious health problems.

More and more countries around the world are abandoning the practice of changing clocks in spring and autumn. However, governments face a fundamental question: which time should be made permanent — summer or winter? Permanent summer time makes evenings brighter, which seems appealing — more time for sports, walks, and relaxation after the workday. But behind this convenience lies a serious threat: sunrise shifts a full hour later. As a result, in winter, millions of people are forced to wake up and commute to work or school in complete darkness. Doctors warn that morning light plays a key role in setting the internal biological clock, ensuring quality sleep, and maintaining stable emotional well-being.

A lack of morning light directly impacts well-being, triggering seasonal depression, which affects 1 to 3% of Canadian residents, while another 15% experience milder autumn-winter flare-ups of apathy. Children and adolescents are at particular risk. During puberty, their natural sleep schedule already shifts to later times, and the need to get up for school in pitch darkness only exacerbates chronic sleep deprivation. Also at risk are early-shift workers, public transit commuters, and residents of rural areas where street lighting leaves much to be desired.

"Our biological clocks need morning light to stay synchronized with the 24-hour day. Permanent summer time shifts that light an hour later precisely when winter mornings are already at their darkest," noted Ralph Mistlberger, a professor of psychology at Simon Fraser University.

Global experience has already clearly demonstrated what hasty decisions lead to. In 1974, the United States introduced permanent summer time to save energy during a crisis, but repealed the law in less than a year — amid mass protests from parents who feared sending their children to school before sunrise. Russia also switched to year-round summer time in 2011, but returned to winter time in 2014 following a wave of public discontent. A similar experiment in Chile in 2015 also ended with a return to the previous schedule.