Even a one-hour change in the clock can disrupt the body’s circadian rhythms, especially when the clock “goes forward.”
Charlie Riedel/AP
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Charlie Riedel/AP
Even a one-hour change in the clock can disrupt the body’s circadian rhythms, especially when the clock “goes forward.”
Charlie Riedel/AP
Millions of us may lose sleep when the clocks “go forward” an hour this Sunday, as most states switch to summer time. The time change brings darker mornings and prolongs the light in the evening. And some legislators want to make daylight saving time permanent, to avoid the interruption of constant switching.
Sen. Marco Rubio (R-Fla.), who introduced sun protection law of 2023, says the ritual of changing our clocks twice a year “makes no sense” and is “dumb”. He is joined by a bipartisan group of senators including Ron Wyden (D-Ore) and Edward Markey (D-Mass).
The Senate unanimously passed a similar measure in 2022, but it didn’t get enough support in the House of Representatives. Now Senator Rubio is trying again, pointing to the potential health and economic benefits. The key argument is that more light in the evening can entice people to go out and spend more money in shops and restaurants.
The health impacts have been more complicated to understand. But in recent years, the spring time change has been linked to an increase in cardiac events, possibly due to disturbed sleep. One study found a increase in hospitalizations for atrial fibrillation, a type of cardiac arrhythmia, in the days following the change from spring to daylight saving time.
“I was very surprised”, researcher and author of the study Dr. Jay Chudow, cardiologist at Montefiore Health, told NPR last year. “It’s just a change of an hour,” he says, but it shows how sensitive our bodies can be to disruptions in the circadian rhythm.
Many doctors and scientists agree that it’s time to stop the twice-a-year clock change, but they oppose legislation that would make daylight saving time permanent. Instead, the American Academy of Sleep Medicine and the American Medical Association both favor permanent standard time, which preserves morning light.
“Human circadian rhythms are very closely tied to sunrise and sunset,” explains Jennifer Martin, a psychologist who is also president of the AASM.
And she says our internal clock isn’t as well aligned during daylight saving time. “Morning light is very important,” she says. “Restoring permanent standard time year-round is the best option for our health and well-being,” says Martin.
Martin treats patients with sleep disorders. “When I work with people who suffer from insomnia, we work really hard to have a consistent time to get up in the morning. And it’s much easier when it’s light in the morning,” says Martin.
“The Senate has things upside down,” says Dr Pedram Navab neurologist and sleep medicine specialist in Los Angeles. “The natural daily cycle of light and dark,” he says, “is really the most powerful timing signal we have to synchronize our biological clock.”
Daylight saving time increases light exposure in the evening, Navab says, which can make it harder to fall asleep at night. He plans to travel to Capitol Hill in April with the American Academy for Sleep Medicine’s advocacy committee to oppose sun protection law.
The SAMS points a “abundance of accumulated evidence“associating the change from winter time to summer time with an increase in cardiovascular events, mood disorders and car accidents. For example, a study by scientists from the University from Colorado to Boulder, published in Current Biology in 2020, saw an increase in fatal car crashes in the week following the spring time change. But their solution is to make standard time permanent.
As for the explosion in DST-related spending, convenience stores across the country told a congressional subcommittee last year that they saw a increase in expenses when the clocks move forward in the spring. In the 1980s, the National Association of Convenience Stores lobbied to extend daylight saving time for a longer period of the year. “When people come home from work and there’s more daylight, they tend to be more active,” NACS’ Lyle Beckwith told NPR last year. “They go to sporting events. They play softball. They play golf. They barbecue,” Beckwith said. And that translates to more people shopping at convenience stores for everything from water, beer or sports drinks, or to pick up charcoal.
So there seems to be a gap between what is probably best for our health (permanent standard time) and what may be good for the economy (permanent daylight saving time).
Last year, House lawmakers balked at passing the Sunshine Protection Act, citing higher priorities. And, with inflation, a huge budget deficit and a war in Ukraine, this year could see a repeat of that.