In the deep darkness of the early hours of Sunday morning, most Americans will travel back in time.
It won’t be a giant leap, not a trip to medieval times or to visit the dinosaurs, but instead just a tiny step. Magically, 2 a.m. will suddenly shift to 1 a.m.
The time travel won’t be due to some spectacular scientific advancement. No DeLoreans, phone booths or hot tubs will be required.
No, this journey is the result of something much less exciting: government policy.
Sunday marks the end of daylight saving time, meaning clocks across most of the country will be turned back one hour as standard time returns.
And while many people will be excited for the extra hour of sleep the shift will provide, health experts warn the change could have some unwelcome consequences for some. That’s part of the reason why there’s been a push to eliminate the biannual tradition.
How we got here
The story of daylight saving time is not a straightforward one.
The modern idea of annually adjusting clocks dates all the way back to a Founding Father of America. According to multiple sources, Benjamin Franklin proposed the idea as a joke back in 1784, pitching it as a way for the people of Paris to cut down on how much they had to spend on candles.
The idea came up again about a century later, this time proposed by a British builder who was able to get a member of Parliament to author a bill that would shift clocks in April and September. It never became law.
It did, however, become law in Canada in 1908. That’s when, according to timeandtable.com, the residents of Port Arthur, Ontario, decided to set their clocks forward by one hour.
The U.S. joined the party during World War I, implementing its first version of daylight saving time as way to help save fuel as part of the war effort, according to information from the Smithsonian. The country brought back “war time” during World War II, but it was discontinued in September 1945.
By 1965, timekeeping in the U.S. had become chaotic. According to the Smithsonian, at that time 71 of the country’s largest cities were using daylight saving time and 59 weren’t.
The led Congress to in 1966 pas the Uniform Time Act, which split the year in half. On the last Sunday in April each year daylight saving time would begin, and on the last Sunday in October standard time would resume.
Eight years later, in an attempt to address an ongoing national gas crisis, President Richard Nixon signed a law that made daylight saving time permanent. The move proved unpopular, however, and by the end of that same year the law was repealed.
Since then there have been small changes to the dates on which the clocks are adjusted, with things currently standing that they’re moved forward on the second Sunday in March and back on the first Sunday in November.
How changing clocks impact health
While the idea to adjust clocks was born out of economic and energy consumption concerns, little concern was afforded to the health impacts it would have.
And according to local health care experts, there are quite a few.
Dr. Matthew Viereck, a neurologist at Reading Hospital, said most of the impacts are a result of the changing clocks messing with people’s internal clocks.
“Our body has its own internal clock that operates based on circadian rhythms,” he said. “And the body relies on sunlight to maintain those rhythms. So when you shift the clock either way you’re disrupting that rhythm.”
Viereck said there are a lot of different health issues that can arise due to changing the clocks. They typically tend to be worse in the spring when the clock jumps ahead, but some can also pop up in the fall.
When clocks are changed in the spring, he said, it’s common to see a rise in heart attacks, strokes and arrhythmia. There’s even been shown to be a 6% increase in car crashes.
Around the fall change, Viereck said, there are increases in mood disorders, sleep disruption and even suicide.
“We definitely see some profound health risks,” he said.
Dr. Krista Schenkel, a family medicine physician for Penn State Health St. Joseph Medical Group, said she sees a lot more patients battling seasonal effective disorder in the days and weeks after the clocks are turned back.
“That’s increased, definitely, this time of year,” she said. “Especially for people who have a predisposition to depression.”
Schenkel said the change can also be difficult on children, pointing out she’s experienced that firsthand with her own 5-year-old and 9-year-old. The time shift can disrupt their sleep schedules and leave them groggy and grumpy.
“It’s a struggle for them,” she said.
Dr. Alexis Reedy-Cooper, a family medicine physician and director of the Penn State Health St. Joseph Family and Community Medicine Residency Program, said the impacts of the time change likely will last more than just a day or two.
“The adjustment to the new time doesn’t happen right away,” she said. “It takes at least a week, and even longer for some.”
For most people, she said, the impacts will simply be a little tiredness during the day and perhaps some trouble falling asleep at night. But for some they will be more severe.
“It effects everybody, but it will really effect people who are already prone to having issues with their sleep,” she said.
Reedy-Cooper, Schenkel and Viereck all agreed the key to dealing with the time change is routine.
“The big thing is really being mindful of your sleep,” Reedy-Cooper said. “Recognize that it’s going to take a little bit of time to adjust, and be careful and forgiving with yourself for a few weeks.”
Schenkel said going to bed and waking up at the same time each day is an important way to deal with the time change. She also said that for people really effected by having to wake up when it’s still dark outside there are products that can simulate sunlight or the sunrise indoors.
Viereck added that good sleep hygiene is critical, as well. That includes getting enough sleep each night — he recommends seven to nine hours — avoiding caffeine in the evening and not using electronics in bed.
He also agreed consistent times for going to bed and waking up are key healthy sleep habits.
“It’s not just the quantity of sleep, but also the quality and when you sleep,” he said.
Time to end daylight saving?
Not everyone changes their clocks twice a year.
The U.S. is one of only about 70 countries to use daylight saving time, most of which are in North America and Europe. Even in the U.S., two states — Arizona and Hawaii — don’t make the switch.
Which begs the question: Should we keep doing it?
Sleep health experts are clear on the matter. And their answer is a resounding “no.”
The American Academy of Sleep said in a statement published in the Journal of Clinical Sleep Medicine in 2020 that it is unequivocal in advocating for the elimination of daylight saving time.
“The U.S. should eliminate seasonal time changes in favor of a national, fixed, year-round time,” the statement says, later adding that standard time best aligns with human circadian rhythms.
Local medical experts support that stance.
“I think most of the medical community, and even politicians, agree that we should avoid this shifting,” Viereck said.
Schenkel said she 100% agrees with making standard time a full-time thing.
“From a health perspective, if you’re not sleeping right at night and you’re having it twice a year where you sleep is being thrown off by an hour, your health is going to be off,” she said.
Reedy-Cooper said she believes daylight saving time is something that’s time has come and gone.
“It was useful back in the early 1900s when electricity wasn’t around that much, but the reasons for it don’t make sense anymore,” she said. “While clinically the evidence isn’t perfect and it needs to be studied more, it points to it as not being beneficial to us as human beings.
“The risk of messing with circadian rhythms twice a year is worse than any advantage.”
There have been efforts to eliminate the biannual time changes, most recently through the Sunshine Protection Act first introduced by U.S. Sen. Marco Rubio of Florida in 2021.
That bill would would make daylight saving time permanent, eliminating standard time. While the legislation was unanimously passed by the Senate in 2022, it has since stalled.
