What winter time does to your sleep, and what you can do about it

In the night from Saturday, October 24 to Sunday, October 25, 2026, clocks across the European Union will go back one hour. You get an extra hour in bed, yet many people feel out of sorts the following week. That isn’t due to that extra hour. It’s because your body runs on sunlight while your schedule runs on the clock on the wall. Below is exactly what happens, what has and hasn’t been demonstrated, and what you can do this week.

Two clocks out of sync

Your body has its own clock with a cycle of approximately 24 hours. The term circadian comes from the Latin circa dies, meaning about a day. That clock doesn’t run perfectly on its own: it is reset every day by light, especially morning light. Morning light sets your clock earlier; evening light delays it.

When switching to winter time, the sun rises an hour earlier according to the clock. If you get up at seven o’clock, it is lighter outside than the day before. That helps your clock. However, your body continues on the old rhythm for a few days, so it wants to wake up an hour earlier than the alarm requires. This is why early birds especially wake up too early during the first few days. Night owls notice it less, as they actually gain an hour of leeway.

What has been proven, and what hasn’t

The most honest overview comes from a systematic review in the European Journal of Epidemiology (Steponenaite and colleagues, 2026), which compared 157 studies from 36 countries. The outcomes differ significantly per switch.

• After the switch to daylight saving time in the spring: a short-term increase of approximately four percent in heart attacks in the first weeks, and more fatal traffic accidents.
• After the switch to winter time in the autumn: lower all-cause mortality, fewer workplace accidents, and possibly a slightly longer sleep duration. However, there are more violent crimes involving injury.
• For psychological outcomes, researchers found no consistent pattern.

This weekend’s switch is the milder of the two. Spring is the problem.

There is a caveat to be made here that the researchers themselves point out: only about one in five of those 157 studies is of high quality, and a true meta-analysis was not possible. Anyone telling you this week that winter time is proven to be bad or proven to be good for you is going further than the evidence allows.

The real risk lies in the evening rush hour

There is a clear pattern here. The Belgian road safety institute Vias compared November with October over the period from 2016 to 2025 for the evening rush hour between 4:00 PM and 7:00 PM. In November, injury accidents involving pedestrians are 39 percent higher than in October, and serious accidents are 73 percent higher. For every thousand injury accidents, there are 109 deaths or serious injuries in October, compared to 136 in November. Over ten years, the November evening rush hour accounts for 181 deaths and serious injuries among pedestrians, an average of eighteen per year. For cyclists, there are approximately four times as many accidents in the twilight in November as in June.

The mechanism is not fatigue, but visibility. Vias spokesperson Stef Willems put it this way: journeys that people previously made in daylight now happen in the twilight or in the dark. Drivers see pedestrians later or not at all, and therefore brake later or not at all. Vias is cautious with its conclusion: these figures alone do not prove that winter time is worse for road safety; figures from daylight saving time are also needed for that.

In practical terms, this means that in the first weeks after the switch, you should let your own visibility make the difference: lights and reflection on your bike, light-colored or reflective clothing as a pedestrian, and extra caution when crossing in places where parked cars obstruct the view.

The winter blues, and why morning light is more than just a tip

The shorter days coincide with an increase in seasonal complaints. The proportion of people with seasonal affective disorder (SAD) is estimated at three to five percent, according to Johan Verbraecken, medical coordinator of the sleep centre at Antwerp University Hospital (October 2026). Additionally, there is a much larger group with milder symptoms: less energy, a greater need for sleep, and increased cravings for carbohydrates.

Why this is related to light is clearly explained in an analysis in the Canadian Medical Association Journal from October 5, 2026, by Raymond Lam (University of British Columbia) with Ralph Mistlberger and Patrick Baylis. Light therapy in the morning is one of the best-researched treatments for winter depression. A time setting that pushes morning light back actually undermines that signal. The authors are also honest about the downside of permanent winter time: in the summer, the sun would rise very early, and in the winter, it gets dark early, which limits outdoor activities after work.

For you this week, the practical point is simpler: morning light is the most powerful tool you have, and it’s free. Even on a grey day, it is much brighter outside than indoors under artificial light.

What to do this week

• Go outside within the first hour after waking up, for ten to twenty minutes. This is the signal your clock uses to reset itself. A short walk or having your coffee outside is enough.
• Stick to your wake-up time, even on the weekend. That is the only anchor that works every day. Your bedtime will follow naturally.
• Do not move your bedtime forward. If the switch causes you to wake up too early, going to bed earlier is exactly the wrong move. Stick to your normal bedtime, and your rhythm will be back in place within a few days.
• Dim the lights in the last two hours before you go to bed. Bright light in the evening delays your clock, which is exactly what you don’t want right now.
• A nap is allowed, but preferably before 3:00 PM and for no longer than twenty minutes. Longer or later naps reduce the sleep pressure for your evening.
• Pay attention to your visibility in traffic; see the figures above. This is the most concrete health risk this week.

In much of western Europe, the clock is already off

There is a reason why the switch hits harder in western Europe than in the centre of the continent. Central European Time is based on the 15th meridian, which runs through eastern Germany. Spain, France and the Benelux countries, however, lie geographically in the London time zone, yet have followed Central European Time since World War II. As a result, solar noon there falls around 1:00 PM in winter and close to 2:00 PM in summer, and in western Spain even later. Much of western Europe is therefore structurally living ahead of the sun, and summer time adds another hour on top of that. Chronobiologist Roelof Hut from the University of Groningen: our biological clock focuses primarily on the sun, and that doesn’t change.

For those regions, winter time is therefore not an ideal, but a compromise that is closer to the sun than the alternative. Most European countries reintroduced summer time in the 1970s and early 1980s, originally to save energy. That effect on energy consumption has proven negligible in later research.

Where the politics stand, and what that means for you

The United States has not yet chosen

On July 14, 2026, the U.S. House of Representatives passed the Sunshine Protection Act by 308 votes to 117. That law would make daylight saving time permanent. President Trump openly supported the proposal. However, it is not yet law: the proposal has since stalled in the Senate Committee on Commerce, Science, and Transportation. Senate leader John Thune has publicly doubted whether there are sixty votes to open the debate, and Senator Tom Cotton is leading the opposition with the argument of dangerously dark winter mornings for commuters and schoolchildren. The Senate does not return to Washington until November 9, which is after the American clock change on November 1. The American Academy of Sleep Medicine already rejected the vote on July 15, 2026, and advocates, like European sleep science, for permanent standard time.

The direction of the American debate remains interesting, as it is the mirror image of the European one. The US is opting for more evening light: which is good for hospitality, tourism, and outdoor activities after work. Europe leans toward more morning light, because that better suits the biorhythm. The fact that what feels good and what is good for your clock are not necessarily the same is the very core of the discussion.

That permanent daylight saving time is poorly received in practice has already been tested three times. The United States reversed it in 1974, Russia between 2011 and 2014, and Chile in 2015.

Europe has not yet decided

Directive 2000/84/EC still applies, requiring all member states to change their clocks on the same day. Member states cannot opt out individually. The European Commission proposed abolishing the clock change in September 2018, the European Parliament agreed in March 2019, and the Council of Ministers has never reached an agreement: Southern Europe leans toward permanent daylight saving time, Northern Europe toward permanent winter time. Spain put the subject back on the agenda in October 2025. The Commission is now having a study conducted on the various scenarios, which should be ready by the end of 2026, to break the deadlock in decision-making.

For you, this means the following: the switches for 2027 are already fixed for March 28 and October 31. Almost certainly, nothing will change in the next two years.

Where European sleep science stands

In 2019, the European Biological Rhythms Society and the European Sleep Research Society, together with the Society for Research on Biological Rhythms, wrote to the European Commission that permanent standard time is the best option for public health. A literature review by the Dutch public health institute RIVM (October 15, 2019) reached the same conclusion: permanent standard time, i.e. winter time, is more favourable than permanent summer time, because the sun rises earlier, which better fits the human rhythm. Public opinion agrees on at least one point: in the European Commission’s 2018 consultation, 84 percent of the 4.6 million respondents wanted to stop changing the clocks.

The most famous figures in this debate come from the United States, and they deserve a caveat. Lara Weed and Jamie Zeitzer from Stanford modeled the health effects of both permanent choices in PNAS on September 15, 2025. In their model, permanent winter time resulted in approximately 2.6 million fewer cases of obesity and 300,000 fewer strokes. However, permanent daylight saving time also showed gains compared to the current switching system: approximately 1.7 million fewer cases of obesity and 220,000 fewer strokes. According to this model, the switching itself is the main problem, and winter time is the better of the two fixed options. Zeitzer himself warns that the models assume more favorable light habits than people actually have. Additionally, José María Martín-Olalla (University of Seville) and Jorge Mira (University of Santiago de Compostela) questioned the metric used to calculate those health gains in PNAS in 2026. Treat these figures as a direction, not a precise scale.

When it’s more than just getting used to it

For most people, the switch is resolved within a few days to two weeks. If things don’t improve after that, you are no longer dealing with the clock but with something else. Consider insomnia that occurs at least three nights a week for longer than three months, daytime exhaustion despite enough time in bed—which could point to sleep apnoea—or a mood that remains low for weeks. That is not a matter of sleep hygiene, and for that, you should see your GP. Sleep complaints are highly treatable, but first, it must be clear what is going on.

In conclusion

The hour you get back this weekend is not the problem. Your rhythm will be a bit confused for the first few days, your evening rush hour will be dark, and your mornings will temporarily be lighter. Of those three things, the last is the most useful: use that morning light. Furthermore, the underlying debate is more important than the switch itself, as in much of western Europe the clock is structurally ahead of the sun, and science points toward standard time for the long term.

Next step: if you want to work specifically on your sleep rhythm instead of waiting for every clock change, SleepGrip offers a program based on cognitive behavioral therapy for insomnia that you can follow at home. If you are unsure whether your bed and sleep environment are helping or hindering your rhythm, that is a conversation for the showroom floor.

Resources

• Steponenaite and colleagues (2026). A systematic review of epidemiological studies into daylight-saving time and health identifying beneficial and adverse effects. European Journal of Epidemiology. doi 10.1007/s10654-026-01372-8
• Vias institute (October 22, 2026). Statistical analysis of pedestrian accidents in the evening rush hour, November versus October, 2016 to 2025.
• Lam RW, Mistlberger R, Baylis P and colleagues (October 5, 2026). Analysis of health impacts associated with adopting permanent standard time or permanent daylight saving time to inform policy in Canada. CMAJ 198(34):E1335-E1340. doi 10.1503/cmaj.261089
• Weed L, Zeitzer J (September 15, 2025). Circadian-informed modeling predicts regional variation in obesity and stroke outcomes under different permanent US time policies. PNAS. doi 10.1073/pnas.2508293122
• Martín-Olalla JM, Mira J (2026). The sum of absolute circadian shifts: questioning the metric linking daylight saving time policy to stroke and obesity. PNAS 123(17). doi 10.1073/pnas.2532075123
• RIVM (October 15, 2019). Standard time, daylight saving time and health: literature review of health effects of different time settings.
• European Biological Rhythms Society, European Sleep Research Society and Society for Research on Biological Rhythms (2019). Joint letter to the European Commission on permanent standard time. European Commission (August 31, 2018). Results of the public consultation on summertime arrangements. See also Hersenstichting (position since October 25, 2022, updated September 29, 2025): Government must quickly decide on permanent daylight saving or winter time.
• American Academy of Sleep Medicine (July 15, 2026). Statement on the passage of the Sunshine Protection Act by the House of Representatives.
• European Commission, representation in the Netherlands (March 25, 2026). Ministers receive help to reach an agreement on clock changes.
• Directive 2000/84/EC of the European Parliament and of the Council on summer-time arrangements.
• Roelof Hut (University of Groningen) and Johan Verbraecken (UZ Antwerp), quoted in Scientias, October 6, 2026.