We will spend the night from Saturday to Sunday in summer time, giving up an hour of early sleep in exchange for later sunshine in the evening. This discrepancy, practiced for a century in Canada, is increasingly questioned by scientists. They question the energy savings it is supposed to provide and, above all, are concerned about its consequences on the population’s biological clock.
To change the time or not, that is the question.
Like Germany and Great Britain, the Canadian government adopted daylight saving time during the First World War. The bet was that as the sun set “later”, workers and farmers would be able to work longer in daylight, increasing their productivity and at the same time saving the energy needed for lighting. Shelved at the end of the Great War, the measure was reinstated during the Second World War. Since then, it has been used in Canada, the United States and the countries of the European Union, in particular.
This move to daylight saving time is increasingly being called into question. The Canadian Sleep Society and the Canadian Society for Chronobiology have, among others, spoken out in favor of a return to standard time throughout the year.
Real consequences
This is because beyond the endless annoyances surrounding the setting of the microwave clock, the time change also has physical consequences on the body, explains Roger Godbout, sleep specialist and full professor in the department. of psychiatry and addictology from the Faculty of Medicine of the University of Montreal.
First, the time change often results in loss of sleep. Which, in the following days, can result in drowsiness, mood and concentration disorders, as well as memory loss. Studies also highlight that there is an increase in road accidents and myocardial infarctions in the days following the time changes.
“Sunday morning, the effect is not too serious. But Monday morning, when people go back to work, [ça va être plus difficile] », illustrates Mr. Godbout. Time changes are also particularly annoying for people following strict schedules, such as patients in medical institutions who are fed or put to bed at the same time systematically.
The time change also has the effect of disrupting our biological clock, which is set by morning light and maximum illumination at midday, when the sun is at its zenith. This sudden imbalance therefore destabilizes our circadian rhythm. “In the long term, all our hormones, our neurotransmitters and the synchronization of all our biological clocks are disrupted,” mentions Professor Godbout.
The energy savings achieved by fiddling with the clock hands are also being questioned.
According to ADEME, the French government agency for ecological transition, these energy savings are becoming increasingly meager. While in 1996, they represented 1,200 gigawatt hours of electricity on French territory, today they are only 351 GWh, the fault of more efficient lighting systems and low-consumption bulbs.
So, should we stop or not?
Faced with these arguments, the pure and simple abandonment of the time change goes a long way. Already, several countries have abolished the practice, including Russia, Argentina, Turkey, and Mexico (except for cities bordering the United States). In Canada, moreover, Saskatchewan has not changed the time since the middle of the 20th century.e century. And the Yukon followed suit in 2020.
“There is absolutely no reason why we need to change the time twice a year as we do. It’s harmful to your health,” says Roger Godbout.
However, the total abandonment of the time change in the country seems unlikely in the short term, since, due to trade, Canada remains closely linked to the United States on this issue. Professor Godbout still has an idea to make the transition to daylight saving time less painful. “It would be a lot better if we changed the time on Friday rather than Saturday. We would gain a day to adapt” and Mondays would be less laborious, observes the researcher.