Ways to help the body adjust to winter time

The body determines the time of day not by the numbers on the clock, but by light signals sent from the eyes to the suprachiasmatic nucleus — the brain’s main clock, which sets the circadian rhythm. Bright evening light suppresses the production of melatonin — a hormone that signals biological night — and shifts the internal clock to a later time. This also explains why, in summer, during the long, bright evenings, many people feel less inclined to sleep at their usual time. Even the light from phones and e‑books contributes to the suppression of melatonin.

Therefore, as you get closer to bedtime, switch to soft, dim lighting and reduce the brightness of your screens. In the hours before sleep, the light exposure should be minimal, and the bedroom should be as dark as possible.

There’s also a nuance related specifically to the autumn time change: it gets dark earlier, and you start feeling sleepy earlier than usual. If you’re falling asleep and waking up too early, it’s useful to slightly shift your internal clock to a later time. To do this, prepare for sleep only before the bedtime you’re aiming for; don’t spend the entire evening in the dark after sunset.

A walk, lunch outdoors, or simply spending more time outdoors helps to enhance the contrast between the bright daytime and the dark evening. It is this contrast that synchronizes the circadian system, which developed under conditions of a much more pronounced cycle of light and darkness than the modern indoor lifestyle provides.

It matters when exactly you receive light. Morning light shifts the internal clock to an earlier time, evening light — to a later time. After switching to daylight saving time, those who wake up too early do not need an additional signal for early awakening: it is better to get daylight during regular waking hours, rather than deliberately seeking bright light at an unusually early hour. A practical option is a walk during the lunch break.

If the problem is early evening drowsiness, it is better to spend time outdoors towards the end of the day, while it is still light, rather than in the morning. There are also model calculations from 2024 that predicted that light in the second half of the day could accelerate adaptation to the autumn time change; however, the authors emphasized that these proposals still require experimental verification. So, daylight should be seen as a useful daily cue for the body.

An extra hour of sleep is tempting to reorganize on weekends: go to bed earlier, get up later. But regularity is the key factor here. Sleep depends on two processes: sleep pressure, which accumulates during wakefulness, and circadian signals, which determine when you feel sleepy or awake.

Strive for roughly the same bedtime and wake‑up time according to the new time zone. A similar schedule on weekdays and weekends supports healthy sleep. If you still can’t fall asleep even with a stable routine, engage in a quiet activity in dim light until you feel ready for sleep. Dark autumn mornings can also make waking up more difficult: a roughly consistent wake‑up time, morning light when possible, and sufficient sleep duration will help, although some drowsiness immediately after waking up is completely normal.

With early winter dusk, it becomes harder to get through the second half of the day, and coffee seems like the obvious solution. Caffeine interferes with sleep long before its stimulating effect wears off. In a recent small study, a dose of 400 mg of caffeine (which is roughly 3–5 cups of coffee) affected sleep even when consumed eight hours before bedtime. The dose is certainly large, but not everyone drinks that much in the middle of the day.

Fortunately, the same study showed that 100 mg of caffeine (one cup of coffee) consumed four hours before bedtime did not affect sleep — there was no difference compared to a placebo. If sleep is difficult, it’s wise to move the last caffeine‑containing drink to an earlier time and reduce its amount. Evening caffeine also shifts the internal clock to a later time, so giving it up will help those who are trying to maintain an earlier sleep schedule.

Most people adapt to the winter period with its short daylight hours within a few days or about a week, although some need more time. But if sleep problems haven’t resolved after a month, the issue is likely not just about the time change — you should look for another cause.