Debating the Health and Convenience of Daylight Saving vs. Standard Time

The Implications of Daylight Saving Time on Health and Society

From the timeless debate over the chicken or the egg to the preference for cats or dogs, some topics generate spirited discussions. Among these is the topic of daylight saving time versus standard time, a subject that can elicit strong opinions even from the most reserved individuals. The question remains: which system is more beneficial?

Researchers Muzhe Yang, Susan Averett from Lafayette College, and Laura Argys from the University of Colorado Denver have explored this issue extensively. Their study, “Living in Sync with the Sun”, published in the American Journal of Health Economics, investigates how daylight saving time impacts health and our circadian rhythm.

Unlike most research that focuses on short-term clock changes, Yang and his colleagues examined the long-term effects of circadian misalignment. Their study particularly looked at individuals living near time zone borders, where solar time remains consistent but clock time can differ by up to an hour during standard time and two hours during daylight saving time. The analysis revealed that individuals living on the eastern side of these borders experience worse mental health outcomes.

“Our study looks at a comparison between the two sides of a time zone border,” Yang explains. “It is equivalent to estimating the health impact of moving a person from one side of the border to the other side. And it is essentially the comparison between choosing permanent daylight saving time, which is moving to the east side, and choosing permanent standard time, which is moving to the west side.”

Yang describes circadian misalignment as the discord between our daily activities and our natural rhythms, which are primarily governed by the sun. The discrepancy between solar time and clock time can lead to health issues over time, particularly when solar noon does not coincide with noon on the clock.

The study’s findings indicate a 6% increase in diagnosed depression cases among people on the eastern side of time zone borders. “That sounds small, but across millions of people, that will become meaningful, especially because depression is costly and deeply tied to quality of life,” Yang notes.

Yang identifies three main insights from the research. Firstly, the choice between daylight saving time and standard time is not just a matter of time policy but also health policy. While daylight saving time offers benefits like more evening daylight, which can boost economic and recreational activities, standard time is better for sleep and mental health.

Secondly, the study highlights that long-term, even minor circadian misalignments can accumulate, measurably shifting population-level health risks. Yang emphasizes that even without the one-hour clock shift, living slightly out of sync with solar time over extended periods can have adverse effects.

Finally, Yang suggests potential solutions don’t have to be absolute. For instance, adopting standard time could be balanced with flexible work schedules or redrawing time zone boundaries. Europe is already considering time zones where the difference between clock time and solar time would not exceed 30 minutes.

“Even if there are benefits of daylight saving time, we should also consider what the net effect is once we factor in health,” Yang states. “Our paper adds evidence on that health side focusing on the impact of this year-round chronic misalignment that will be exacerbated when we permanently move our clock forward by one hour.”