Arts & Sciences

WashU Expert: Time to retire daylight saving time

Saying goodbye to daylight saving time, and the summertime memories we associate with it, can be difficult. But scientists who study biological clocks and sleep — including Erik Herzog, professor of biology in Arts & Sciences — remind us that we need sun in the morning. (Photo: Shutterstock)

Change is upon us once again. Come the first Sunday of November, we will gain an hour of morning sunlight. The one-hour adjustment to the clock on the wall may not sound dramatic. But our biological clock begs to differ.

Take, for example, the members of society blissfully unaware of social time: our youngest children and pets. While many will soon enjoy an extra hour of sleep, our children and pets will be the first to wake. It will be a few more days before their biological clock adjusts to the new social time.

In fact, most of us need a few days to adjust to time changes. In the meantime, we may suffer some consequences.


“Heart attacks and traffic fatalities increase in the days following the change to daylight saving time (DST) in the spring,” said Erik Herzog, PhD, professor of biology in Arts & Sciences and past president of the Society for Research on Biological Rhythms, a scientific organization dedicated to the study of biological clocks and sleep.

Recently, a 2020 study quantified a 6% increase in traffic fatalities in the days following the time change to DST. Six percent translates to 28 fatalities in the United States per year because of time switching — a tradition that most, including Herzog, agree it is time to retire.

Yet, here we are nearing November 2021, preparing to adjust to a social change once again with no help from the sun, which will rise and set on its own schedule. What is holding us back from eliminating time changes?

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