How does daylight saving time impact your health?

(NewsNation) – Twice a year, daylight saving time brings a major change to many Americans’ schedules, sending clocks back an hour in 48 states. This year, clocks go back an hour on Nov. 1 to standard time.

While a 60-minute difference may not seem like much, it has a major impact on many aspects of human life and health. Sleep is impacted, as well as metabolism, mental health and vascular health. Effects can be temporary or long-term.

The biannual change has been debated. Dozens of states — and countries — have suggested and pitched legislation for a switch to permanent standard time, which the Society for Research on Biological Rhythms deems “the best option for public health.”

“The more light exposure you get at the wrong times, the weaker the circadian clock. All of these things that are downstream — for example, your immune system, your energy — don’t match up quite as well,” said Jamie Zeitzer, professor of psychiatry and behavioral sciences at Stanford University, who authored a 2025 study on daylight saving time

History of daylight saving time

Only about one-third of the world has seasonal time changes. Canada and many countries in Europe observe it. But many countries that used to participate have stopped doing so over the last 10 years, including Mexico, Brazil, Iran, Russia, Syria and Turkey.

Daylight saving time in the United States had a bumpy beginning. After multiple failed attempts, the Uniform Time Act of 1966 made daylight saving time law. One of the main motivators was transportation improvements.

According to the Bureau of Transportation Statistics, “This act mandated standard time within the existing time zones and established a permanent system of uniform DST, including the dates and times for twice yearly transitions.”The act includes some local exemptions. Arizona, Hawaii and some U.S. territories do not participate in the time change, mainly due to long hours of sunshine and high temperatures.

During a time change trial run in Arizona, where the day starts around 5 a.m. in summer and the sun sets at 8 p.m., energy consumption went up, and in summer, activities or work done outside had to wait until after sunset.

Over the years, changing or eliminating DST in the U.S. has been a major talking point. Nexstar’s NewsNation wrote recently about three proposed adjustments currently being considered:

• The Sunshine Protection Act, which has not yet made it past the Senate, would switch the U.S. to standard time year-round.
• Sunshine for Our Kids Act was a similar bill, with a caveat of letting states decide to make daylight saving time permanent without congressional action.
• Daylight Act of 2026 would make the clocks fall back or forward 30 minutes instead of an hour.

  Daylight saving time’s impact on health

  DST brings both benefits and negative effects to health. Both the hour back in fall and forward in spring impact our circadian rhythm, which can take days to weeks to adjust.

  Young people and night owls have the most difficulty with the spring change, according to Dr. Stephanie M. Stahl, a professor at the Indiana University School of Medicine.

  People who already have sleep issues are more at risk of health issues from the time change, whether it’s due to trouble falling asleep later or waking earlier.

  Spring daylight saving brings more sunlight, which leads to more vitamin D production and a chance to get more outdoor exercise. In the fall, there is more sunlight for children going to recess and getting on the bus in the morning, but many people experience seasonal affective disorder as the sun sets earlier.However, in addition to fatigue during the day, the time changes put people at risk of mental health issues, metabolic disorders and heart problems. Both fall and spring time changes have an impact on blood sugar regulation.

  “In the few days after the change to DST, around half of people experience daytime sleepiness,” said Stahl. “Motor vehicle and workplace accidents, heart attacks, strokes, atrial fibrillation, mood disorders and suicide are all increased as well in the few days to weeks after the time change.”

  Because of the associated health and safety issues, the American Academy of Sleep Medicine is in favor of doing away with the changes and switching to a national standard time.

  How to prepare and deal with daylight saving time changes

  Preparing ahead of time and spending the day outside can help combat sleep problems amid daylight saving time. A big part of this is staying in routine and focusing on sleep hygiene — something sleep doctors recommend every day of the year.Simple changes can make a difference, from small schedule shifts and more time outside to reducing light and caffeine intake close to bedtime, shared Amy Rodquist-Kodet, holistic health coach and wellness specialist for UK Health and Wellness, in an essay for University of Kentucky Human Resources.She suggests getting out of bed right away in the morning and avoiding naps over 20 minutes to “preserve the natural sleep pressure that makes it easier to fall asleep at night.”

  “The good news is that small, science-supported habits can make the transition much smoother,” said Rodquist-Kodet. “Instead of pushing through the grogginess, we can gently guide our body clocks into the new rhythm.”