Feeling the Effects of the Time Change? We Asked Experts How to Get Back on Track

Can change the clock Throw you for a loop. Even a one-hour shift, as happens on Sundays in most of the US, can leave you feeling uncomfortable and out of sync for days. That’s because your body’s internal clock—your circadian rhythm—depends on daylight, mealtimes, and a steady routine. When the country’s twice-yearly time changes, it disrupts that rhythm and leaves your body playing catch-up.

The good news is that with a few simple habits, you can help your body bounce back quickly and reset your sleep schedule naturally after a time change. Follow these tips to get back into the groove and start feeling like yourself again after those clocks have rolled

What is Daylight Saving Time?

In the United States, most countries switch between standard time and daylight saving time (DST) in November and March. Standard Time is the “normal” clock time used in fall and winter, while DST is the one-hour shift in spring and summer that changes daylight hours from morning to evening.

Every year, the clocks go forward an hour in March, and we lose an hour of sleep. The clocks turn back to November, giving us back that hour. The idea is to maximize daylight hours for work and play during the warmer months.

Daylight Saving Time Began during World War I as a way to conserve energy. More daylight in the evening meant less need for artificial light, which was in short supply at the time. It was also thought to help farmers by providing additional daylight in the evening. However, since farm work follows the sun, not the clock, this mostly complicates their schedules.

More than a century later, most Americans still follow the same rituals. Exceptions include Hawaii and much of Arizona, where abundant daylight and desert heat make the weather more troublesome than helpful.

Why does time change mess with your body clock?

We tend to focus on how long we sleep, but consistency is just as important, says Rebecca Robbins, a sleep researcher at Brigham and Women’s Hospital and Harvard Medical School. “Just as important as sleep duration, if not more so, is the consistency of the sleep schedule,” she says. “Even changing one hour can be enough to shut down our internal circuitry.”

Your circadian rhythm depends on cues like light, food, and routine. Light is super-important here, because it suppresses melatonin, the hormone that tells your brain it’s time to sleep. When daylight changes, so do your hormones.

That rhythm does much more than fatigue. It regulates digestion, alertness, mood and even immune response. When you move forward, you are essentially forcing your body clock out of sync with your environment. Falling back is gentler, because the extra hours of sleep and morning light usually help your rhythm adjust more easily.

Health costs of sleep loss

The effects of time changes can be seen almost immediately. “Car accidents, heart attacks, cardiovascular sequelae, mood disorders—all of these things are elevated during daylight saving time,” says W. Chris Winter, MD, a neurologist and sleep specialist at Charlottesville Neurology & Sleep Medicine. A Studies from the University of Colorado It found that fatal car accidents in the US increased by about 6 percent in the week following the spring shift to DST.

Most Americans are already sleep deprived. “Only 30 percent of Americans are regularly meeting their biological need for sleep,” Robbins says. A lost hour that compounds the debt.