How to Prep Your Body for Turning the Clocks Ahead for Daylight Saving Time

Every second Sunday in March marks the start of daylight saving time (DST), the annual period when clocks are shifted one hour ahead. In 2026, DST officially starts at 2 a.m. on Sunday, March 8.

The loss of one hour of sleep on one night might not sound detrimental to health at first, says Michael Awad, MD, the chief of sleep surgery at Northwestern Medicine in Chicago. But the lost hour can have significant effects, especially for those who are already sleeping less than the recommended seven to nine hours, Dr. Awad explains.

1. Go in With a Good Base of Sleep

The more consistent your sleep schedule is before the switch, the less of a shift your body will have to make when the time change happens, Awad says. And be sure you’re getting enough sleep regularly. If you’ve been sleeping eight hours per night, one night of seven hours will be a lot less problematic than five hours on a schedule that’s usually six.

If you’re not on the healthiest sleep schedule, use the time change as a reminder to reevaluate how much sleep you’re getting and to work on solidifying good sleep habits. “Treat sleep with the same dedication as other habits, like brushing your teeth or going to the gym,” Awad says. “It’s important.”

2. Shift Your Sleep Gradually Starting the Week Before DST

As DST approaches, start rolling your sleep back by about 15 minutes and moving your wakeup time 15 minutes earlier each morning. “That can help your body gradually adjust, instead of being hit with that one-hour time change,” Awad says.

So, if your usual bedtime is 11 p.m., get to bed at 10:45 the Monday before DST begins. The following night, try to call it quits around 10:30 and keep going until you’ve reached the one-hour mark.

3. Push Back Your Dinner Gradually

“Another major driver of our circadian rhythm is food,” Awad says. Eating too close to bedtime can make it tough to fall asleep, because your body is too focused on digestion to think about winding down for the night.

In general, it’s a good idea to stop eating three to four hours before bedtime, Awad says. To prevent any disruption in that schedule, begin shifting your final meal (usually dinner) to an earlier time about one week before DST starts. Awad suggests shifting in 15-minute increments until you’ve hit one hour.

4. Switch All Your Clocks the Night Before DST Starts

Before going to bed the night before DST, be sure to move all your clocks ahead. Doing so may make the time change feel less confusing, says Whitney Hardy, MD, a family medicine physician at Ochsner Health Center in Gretna, Louisiana. Then, you’ll be ready to live according to the new time as soon as you wake up the next day.

5. Start Your Day With Sunlight

While some delay in your circadian rhythm after DST is inevitable, you can use natural sunlight to get your body clock as closely in tune with the sun clock as possible. “Getting light early in the morning is key,” Awad says.

Try to get 15 minutes of sunlight first thing in the morning. If you live in a warmer climate, you can get your sunlight outside. But even sitting next to the window while you drink your morning coffee will do the trick, Awad says. Later, avoid wake-promoting blue light from cell phones, laptops, and other electronic devices too close to bedtime.

Jumping the clock forward to DST and then back to standard time every year was designed to optimize daylight hours, which has been said to net energy savings, prevent traffic accidents, and reduce crime.

The time change can have effects on your body’s internal clock that last beyond the first night that you “spring forward.” You can think of your circadian rhythm as the internal schedule your body follows, which helps keep daily bodily functions (not just sleeping and waking, but things like metabolism, too) regularly happening at the right times. Your internal clock is accustomed to daylight and darkness consistently happening at certain times of the day. It can take time to adjust to changes, which is why jet lag happens.

“The body doesn’t do very well when it’s asked to live in a different time zone,” says Elizabeth B. Klerman, MD, PhD, a professor of neurology at Harvard Medical School and a sleep research investigator at Massachusetts General Hospital in Boston. Changing the clocks for DST has effects similar to jet lag, which we know can be damaging to health in the long term.

Cues from the sun generally keep these circadian rhythms on track (via a network of cells in the brain referred to as the “body clock”), Awad says. But our behaviors — sleeping in much later than usual on a Saturday, spending a lot of time in the evening in front of bright screens (which the body registers as stimulating sunlight), or eating a big meal in the middle of the night — can send mixed messages to the body and misalign the body’s various circadian rhythms.

Traveling across time zones and switching the clocks for DST have similar effects, misaligning your body’s clock to the one on the wall and the rotation of the sun, Awad explains. DST results in more hours of darkness in the morning, and more hours of daylight in the evening.

“Nighttime light and morning darkness shift your body to a later time, but the social clock has moved to an earlier time, so it’s harder to fall asleep, and people get less sleep,” Dr. Klerman says. “And we know that many bad things happen from not getting enough sleep,” she adds.

DST’s Body Clock Effects on Heart Health

Our bodies will, of course, adjust to the new schedule after a few days or a week, but there’s evidence that the change may still affect our health, particularly heart health.

The mechanisms behind this phenomenon are still up for debate, and research is ongoing. But it may be that DST disrupts the regular release of the stress hormone cortisol, which may make existing heart problems worse and increase the risk of heart problems in older adults, according to Jamie M. Zeitzer, PhD, a research professor at the Stanford Center for Sleep Sciences and Medicine in Palo Alto, California.

• In 2026, daylight saving time (the annual period of the year the clocks are shifted one hour ahead) officially starts at 2 a.m. on Sunday, March 8.
• A shift in your sleep and wake schedule, even just by one hour (as happens during DST) can have health effects, including on your heart.
• Take steps ahead of time, such as maintaining a consistent sleep schedule, getting morning sun exposure, and gradually introducing the change over the course of the week before to ease the transition.