Every year, at the end of October, we turn the clock back one hour and switch to winter time. For some this means an extra hour of sleep, for others a disruption in their daily rhythm. While winter time is often seen as a welcome opportunity to catch some extra rest, its effect on our sleep and health is more complex than you might think. In this article, we dive deeper and look at the impact of winter time on your sleep. We also provide tips for adjusting your body to the change and discuss how to make this transition as smooth as possible.
Winter time, by the way, was also the real or normal time until 1977. Since then, during the sunnier months of the year, the clock was set forward one hour on winter time to save energy. Meanwhile, studies indicate a negligible difference in energy consumption, but numerous health side effects.
What exactly happens to your body during the transition to winter time?
Changing from summer to winter time sets your biological clock back another hour. This can particularly affect the internal biological clock that regulates your sleep-wake cycle. Research has shown that this shift can temporarily disrupt the circadian rhythm, which is often closely linked to natural light. As a result, some people may experience fatigue, mood swings and disturbed sleep quality.
Circadian or biological rhythm describes what happens in your body in a cycle of about 24 hours or, therefore, about a day. The term comes from the Latin “circa dies,” which literally means “about a day.
Scientifically proven effects
Several studies show that our sleep quality in wintertime sometimes improves because of the longer nights. The longer absence of light leads to more production of melatonin, a hormone that promotes sleep. Still, the sudden change in sleep patterns can have negative effects. It is important to realize that even a small shift in time can have an effect on sleep patterns, especially for sensitive sleepers. Evening people are slightly less affected by this and often get used to winter time more quickly.
Our internal clock generally prefers a fixed routine, and any disruption can cause temporary fatigue or sleep problems. Moving the clock can certainly be considered a disruption. Especially in the far corners of the time zone, for example in Belgium, France and the Netherlands, the effects come in even harder. Although it must be said that the impact of daylight saving time is described by many scientists as more intrusive.
Tips for a smooth transition to winter time
- Adjust your sleep schedule gradually: Start adjusting your bedtime a few days before the official switchover. Go to sleep 10 to 15 minutes earlier each day so that the transition is less abrupt.
- Stick to a regular rhythm: Despite the time change, try to maintain a regular sleep routine. Go to bed around the same time every day and get up at a consistent time.
- Avoid bright lights in the evening: Bright lights can inhibit melatonin production. So dim the lights at night in your home.
- Get plenty of daylight: Exposure to natural light in the morning helps your internal clock adjust to the new rhythm. Even a short walk or a cup of tea in the morning sun can make a big difference.
- Listen to your body: If you notice you are tired, try to catch some extra sleep instead of forcing yourself to stay awake. This helps your body better adjust to the new rhythm. Naps are best before 3 p.m. and best no longer than 20 minutes.
Interesting facts about winter time and health
- There are fewer traffic accidents: Research shows that the number of traffic accidents decreases after the transition to winter time because people drive less in the dark during peak hours, thus increasing visibility.
- Effect on winter depression: The shorter days in winter can exacerbate symptoms of the so-called winter dip. Sufficient daylight exposure is crucial to counteracting this.
- Benefits for evening people: If you are a chronotype evening person, you will find that winter time better matches your biological rhythm. Morning people experience a mini jet lag. They transition best slowly to the new awakening time.
- Tired of changing between winter and summer time? Well, you’re not the only one! Unfortunately, there is no unanimity in Europe, which is why individual member states can decide for themselves whether to say goodbye to constantly changing from winter to summer time. The Polish government, for example, has already implemented this. Would you like to sign the petition? Then click on this link and sign!
- The far corners of the time zone are wrong anyway: Why? Until 1914, for example, “English time” was used in Belgium. Several world wars changed this. Specifically, for the low countries, this means that in winter it is noon around 1 p.m. and in summer a little before 2 p.m. So in summer we already deviate 2 hours from the ‘normal’ daily schedule. With all its consequences for the biorhythms of many people.
What will the rest of the world choose? The U.S. is opting for permanent daylight saving time, while Europe is leaning toward standard time
On July 14, 2026, the U.S. House of Representatives voted by a large majority (308 to 117) in favor of the Sunshine Protection Act: a law that permanently establishes daylight saving time in the U.S. No more time changes, and no more returning to standard time. President Trump openly supported the initiative, and the vote cut across party lines.
What stands out: The U.S. is thus deliberately choosing the opposite of what most European sleep scientists recommend. While European experts and organizations such as the Brain Foundation advocate for permanent standard time, the U.S. is opting for more evening light. The reasoning is understandable: more daylight after the workday encourages outdoor activities, supports the hospitality industry and tourism, and reduces traffic accidents during the evening rush hour. European experts believe that standard time (winter time) best aligns with our circadian rhythm.
But from a sleep science perspective, there are risks involved. A 2025 Stanford study modeled the long-term effects of both options on the health of the U.S. population. The researchers calculated that permanent standard time would result in 2.6 million fewer cases of obesity and 300,000 fewer cases of stroke. Permanent daylight saving time also showed health benefits compared to the current system of changing the clocks twice a year, but to a lesser extent. The reason lies in morning light: the biological clock needs morning light as its primary synchronization signal. Permanent daylight saving time shifts daylight into the evening and deprives people of that valuable morning light, especially during the winter months. In some U.S. cities, the sun would not rise until 9:30 a.m. in the winter.
The U.S. decision illustrates a fundamental tension: economic and social logic sometimes conflicts with circadian health. What feels good (more light in the evening) and what is good for your circadian rhythm are not always the same. The European debate has not yet been settled, but the scientific consensus clearly points to standard time as the healthiest option.
Conclusion
The transition to winter time is an annual moment of confusion and disruption for many, but with a few adjustments, you can minimize the impact on your sleep and well-being. By gradually allowing your body to get used to the change and consciously managing daylight, you can make the most of these dark months. Ultimately, the most important thing is to listen to your body and respect your own limits.
It is important that Europe quickly decides to make winter time permanent. This is also the opinion of the Brain Foundation through Koko Beers: “It has been scientifically proven that making our winter time (standard time) permanent is best for public health. By changing the clock your biological clock has to adjust every time, which is not easy for everyone. Permanent winter time best suits our day-night rhythm and causes the least disruption in sleep. People get more morning light in winter and less evening light in summer. For our biological clock, we desperately need that very morning light.”
The recent vote in the U.S. House of Representatives (July 14, 2026) shows that this is a topic of lively debate worldwide, but also that economic arguments and circadian science do not always point in the same direction. The U.S. is opting for more evening light, while Europe is leaning toward more morning light. Who is right? At the moment, the science is on Europe’s side.
Source reference:
This article is based on insights from the Brain Foundation, VRT NWS, Slaapwaarde, nbcnews.com, the American Academy of Sleep Medicine, Kolla et al. (2020), and the Mayo Clinic / Stanford (2025) – “Circadian Health Impact of Time Policy in the Continental U.S.” and “Gezond Leven.”
