The twice-yearly clock change can disrupt your sleep and leave you feeling groggy. Even a one-hour shift, like the one most of the US experienced recently, can throw your body’s internal clock—your circadian rhythm—out of sync for days. This rhythm relies on cues like daylight, meal times, and a consistent routine, and disrupting it can leave your body playing catch-up. Fortunately, simple habits can help you reset your sleep schedule naturally and feel like yourself again.
What is Daylight Saving Time?
In most of the US, clocks switch between standard time (used in fall and winter) and daylight saving time (DST) in November and March. DST shifts daylight from morning to evening by moving clocks forward one hour in the spring and back one hour in the fall. The idea behind this shift, which started during World War I to conserve energy by maximizing daylight hours, is to give people more daylight for work and recreation. While initially intended to help farmers, the practice mostly complicated their schedules as their work follows the sun rather than the clock. Exceptions to this practice include Hawaii and most of Arizona.
Why Time Changes Mess With Your Body Clock
Consistency in sleep schedules is crucial, says Rebecca Robbins, a sleep researcher at Brigham and Women’s Hospital and Harvard Medical School. “Just as important as sleep duration is the consistency of sleep schedules,” she says. “Changing by even one hour can be enough to throw our internal circuitry off.”
Your circadian rhythm, which is governed by light, meal times, and routine, affects far more than just fatigue. It regulates digestion, alertness, mood, and even immune response. Shifting to daylight saving time forces your body’s clock out of sync with your environment, while falling back is gentler, as the extra hour of sleep and morning light typically help the rhythm adjust more easily.
The Impact of Lost Sleep
The effects of the time change can be felt quickly. “Car accidents, heart attacks, cardiovascular issues, and mood disorders tend to be elevated throughout the duration of daylight saving time,” explains neurologist and sleep specialist W. Chris Winter. A University of Colorado study found a 6 percent increase in fatal car crashes in the week following the spring shift to DST.
Compounding the issue is the fact that many Americans already have a sleep deficit. “Only 30 percent of Americans report consistently meeting their biological need for sleep,” Robbins notes. While the effects are typically short-lived for most, experts argue for sticking with standard time year-round to minimize risks.
Preparing Your Body for a Time Change
Preparing for a time change involves gently adjusting your schedule and exposing yourself to more morning light to help your body adapt before the change.
Shift Your Schedule Gradually
The best approach is gradual. Experts recommend shifting your bedtime and wake-up time by 15 to 30 minutes earlier (or later, depending on the season) for a few days before the change, giving your internal clock a chance to recalibrate.
Get Morning Light
Light is a powerful tool. “We, particularly children, do best with morning light,” Winter says. Stepping outside shortly after waking up, or using a light therapy lamp for 15-30 minutes while eating breakfast, can regulate your internal clock.
Time Your Meals Wisely
According to Robbins, meal timing significantly impacts your body clock. An earlier dinner can reduce the risk of insomnia, and consistent meal times reinforce your body’s sense of routine. Consider moving up your dinner by 30-60 minutes in the days leading up to the time change.
Recovering After a Time Change
Even with preparation, the first few days after a time change can be disorienting. It’s important to stay calm and stick to a routine.
Don’t Overthink It
Anxiety about feeling tired can worsen the situation. Winter suggests giving yourself grace; a single hour shift isn’t catastrophic.
Use Short Naps Strategically
A 20-30 minute power nap, ideally before mid-afternoon, can boost alertness without disrupting nighttime sleep.
Keep Evenings Calm
Avoid bright light, heavy meals, and screen time close to bedtime. Find a relaxing pre-sleep routine to signal to your body that it’s time to unwind.
Stick to a Consistent Routine
Go to bed and wake up at the same time every day, even on weekends. Consistent meal times, exercise, and light exposure will help your circadian rhythm relearn its cues.
Should We Even Keep Changing the Clock?
Experts are increasingly questioning the necessity of the semi-annual time change. Standard time, which most of us experience during fall and winter, is generally preferred, as it allows for better alignment with your natural rhythm and morning light exposure. While the policy may change in the future, maximizing standard time offers some benefits.
Researchers are increasingly questioning whether the semi-annual clock flip is worth it at all.
Until the policy changes (or if it ever does), there are some silver linings. Standard time gives you more morning sun and better alignment with your natural rhythm. When DST returns in the spring, that extra evening light can feel like a much-needed morale boost after a long, dark winter.
