Sleep Experts Make the Case Against Daylight Saving Time

The American Academy of Sleep Medicine called for the abolishment of seasonal time changes last week

A man, wearing a hat over his eyes with his shoes off and to his side, and a woman in a kerchief and a blue dress nap together against a haystack; bright orange hay swirls around them, a mule and plow on the horizon
The Siesta after Millet, Vincent Van Gogh, 1890 Public Domain via Wikimedia Commons

For decades, many Americans have fiddled with their clocks each March and November as they “spring forward” or “fall back” to keep pace with daylight saving time (DST). Experts have historically claimed that the practice, which has roots in late 19th century and was widely instituted in 1966, benefits society by extending our sunlit hours and saving energy costs, although many others have called those benefits into question, as Amanda Kooser reports for CNET.

Last week, the American Academy of Sleep Medicine (AASM) entered the debate, calling for the end of DST-related time-changes altogether. Instead, AASM leaders wrote in a statement in the Journal of Clinical Sleep Medicine, the country should abolish seasonal time changes in favor of a “fixed, national, year-round standard time.”

According to the AASM, the biannual switch to DST poses serious health risks, as Allyson Chiu reports for the Washington Post.

“An abundance of accumulated evidence indicates that the acute transition from standard time to daylight saving time incurs significant public health and safety risks, including increased risk of adverse cardiovascular events, mood disorders, and motor vehicle crashes,” the Academy wrote in its statement.

For instance, a recent paper from the University of Colorado Boulder found that fatal car crashes rose by as much as 6 percent during the March “spring forward” work week, when Americans lose one hour of sleep, the Post reports. As the AASM notes in its statement, a research abstract published in May in Sleep found a 18 percent increase in medical errors related to human mistakes during the spring forward period.

As Ed Cara reports for Gizmodo, a report published in Current Biology in January found that the spring forward period was associated with a higher number of fatal car crashes. That same paper estimated that getting rid of DST could have prevented more than 600 fatal accidents in a 22-year period.

“Permanent, year-round standard time is the best choice to most closely match our circadian sleep-wake cycle,” M. Adeel Rishi, lead author on the AASM report and a Mayo Clinic sleep specialist, says in an accompanying statement. “Daylight saving time results in more darkness in the morning and more light in the evening, disrupting the body’s natural rhythm.”

The body’s circadian rhythms, per the National Institute of Health, are the physical, mental and behavioral changes that drive human’s health—otherwise known as one’s “biological clock,” that tells most humans to wake up with the sun and sleep when it goes down. AASM leaders argue that changing to standard time would help align peoples’ social clocks—for instance, when they’re expected to be at work—with their biological ones.

“Standard time is going to be your best situation where your social clock, your internal biological clock and your sun clock are going to be more likely, for the most time, to be better aligned,” as Phyllis Zee, a sleep medicine specialist at Northwestern University’s Feinberg School of Medicine, who was not involved in writing the AASM paper, tells the Post.

“It may not be true for every single person,” adds Zee. “It really depends on where you live, whether you’re an owl or a lark. All of these things matter. But I think overall, as a general policy, that would be the healthiest solution.”

However, not all experts agree that a standard time would be best for human’s biological timetables: “I don’t necessarily agree with the argument that it comports better,” Jamie Zeitzer, a professor of psychiatry at the Stanford Center for Sleep Sciences and Medicine not involved in the AASM paper, tells the Post. “The way our rhythm positions itself is actually quite flexible.”

The AASM acknowledges in its statement that more research is needed to confirm the long-term effects of DST.

As Anna Schaverien reported for the New York Times in May of last year, the European Union voted to abolish the twice-a-year switch. In the United States, as Scottie Andrew reported for CNN in March of this year, 32 states proposed legislation to make DST permanent, therefore eliminating the biannual clock-changes and preserving that precious hour of sleep in the spring, pending Congress’ approval.

Get the latest stories in your inbox every weekday.