4 ways to help your body adjust to the fall time change

An extra hour in bed sounds like a good deal. But while our phones may update to the fall time change automatically, our body clock isn’t quite so quick. You may even find yourself waking up earlier than normal and ready for bed before your evening has properly begun.

The reason for this partly lies in our circadian system: the roughly 24-hour internal timing system that helps organize tiredness and alertness. Changing the time on a clock does not instantly reset that system.

But there are some things you can do to support your body clock in adapting to the time change. While these strategies won’t offer a guaranteed overnight reset, they will help you get back on track.

1. Dim the lights before bedtime

Your body doesn’t judge whether it’s day or night by using the numbers on a clock. Rather, a tiny region in the brain called the suprachiasmatic nucleus (SCN)—which acts as the body’s master clock—uses light signals from the eyes to help keep our circadian rhythm on track.

Bright evening light can suppress melatonin, a hormone that signals biological night, and shift your internal clock later. This can help explain why some people feel less sleepy at their usual bedtime during the long, bright evenings of summer.

But even the light from electronic devices such as phones or e-readers can contribute to melatonin suppression.

So as your intended bedtime approaches, switch to lower, softer lighting and reduce screen brightness. It’s recommended you keep light exposure low in the hours before bed and make the bedroom as dark as practical during sleep.

Of course, the fall time change often means we’re tired before our usual bedtime as night falls earlier. Shifting your body clock a little later can be helpful if you’re becoming sleepy and waking too early.

To do this, only start winding down before the bedtime you want. Don’t spend the entire evening in darkness as soon as the sun sets.

2. Get daylight

A walk, an outdoor lunch break or simply spending more of the day outside can strengthen the contrast between bright days and dim evenings. That contrast helps synchronize the circadian system, which evolved under a much stronger daily light–dark cycle than many indoor lifestyles provide.

When you get this daylight is important, however. Morning light generally moves the body clock earlier, while evening light generally pushes it later. That distinction matters when the clocks go back, because someone waking too early doesn’t necessarily need another signal to wake earlier.

After the clocks change, try to get daylight during your normal waking day rather than deliberately seeking bright light at an unusually early hour. A lunchtime walk is one practical option.

If early-evening sleepiness is the problem, spending time outdoors later in the afternoon, while daylight remains, may be better than prioritizing light first thing in the morning. In fact, a 2024 modeling study predicted that later-day light exposure could speed the fall adjustment. However, the authors emphasized that these proposed interventions still need experimental verification.

Think of daylight as a useful daily cue—not a precisely proven clock-change prescription.

3. Stick to a regular sleep schedule

It’s tempting to treat the extra hour of sleep as permission to overhaul your weekend. But a regular routine is key.

Sleep depends on both the pressure that builds while you’re awake and the circadian signals that determine when you feel sleepy or alert. These processes interact, which is why sleep can’t always be summoned simply by deciding to go to bed.

Aim for reasonably consistent bedtimes and waking times based on the new time. Avoid swinging between very early nights, late wake-ups and late bedtimes. Keeping weekday and weekend schedules similar can support healthy sleep.

If you find that even with a consistent sleep schedule you’re struggling to fall asleep, choose a quiet activity to do in low light until you feel ready for bed.

Dark fall mornings can also make waking up feel harder. Keeping a broadly consistent waking time, getting morning daylight when possible and allowing enough time for sleep may help maintain a stable sleep–wake rhythm—although some grogginess immediately after waking is normal.

4. Rethink your afternoon coffee

The earlier nights that accompany the winter months can make it harder to get through the afternoon. When you feel groggy, coffee can look like the obvious solution. But as much as it pains me to give this advice as a coffee lover, you might want to skip that midday coffee.

Caffeine interferes with sleep long after its effects have worn off. A recent small study found that a 400 mg dose of caffeine (equivalent to around 3–5 cups of coffee) affected sleep even when consumed eight hours before bedtime. That’s quite a substantial dose, of course—and not one many of us are consuming in the midafternoon.

Fortunately, the study also found that when a 100 mg dose of caffeine (equivalent to a single cup of coffee) was consumed four hours before bedtime, it had no effect on sleep compared with a placebo.

If sleep is difficult, moving your last caffeinated drink earlier and reducing the amount you drink are sensible things to try. Evening caffeine can also push the body clock later, so avoiding it may help when you’re trying to keep an earlier sleep schedule.

The fall time change is a useful reminder that sleep depends on more than the number displayed on your phone’s clock. Most people adjust to the time change within a few days to about a week, although some can take longer. But if you’re still struggling a month later, the clock change may not be the whole story.

Who’s behind this story?

Swati Mestri

Swati Mestri holds a bachelor’s degree in Electronics Engineering and has worked as a content editor since 2019. She has experience editing research documents across technology, health care, and materials science, and has a particular interest in technology and space.

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Andrew Zinin

Master’s in physics with research experience. Long-time science news enthusiast. Plays key role in Science X’s editorial success.

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This article is republished from The Conversation under a Creative Commons license. Read the original article.