- In 2026 the clocks go back on Sunday 25 October in the UK and Europe and on Sunday 1 November in the US and Canada. You gain an hour, so the change itself is gentler than springing forward.
- The bigger effect is the darker evenings. Bertel Hansen and colleagues (Epidemiology, 2017) found the switch from summer time to standard time in Denmark was associated with an 11% rise in hospital contacts for depressive episodes, fading over about ten weeks. The spring change had no such effect.
- Thomas Kantermann, Till Roenneberg and colleagues (Current Biology, 2007) found the human body clock tracks dawn across the seasons but does not adjust neatly to the clock change.
- The American Academy of Sleep Medicine's 2020 position statement supports permanent standard time, because it better matches the body clock to daylight.
- What helps most is light early in the day, a steady wake time, and planning for the evening darkness rather than the lost or gained hour.
In This Article
When the clocks go back, you get an extra hour in bed, and the change is gentler on the body than springing forward. But "falling back" has a cost that most coverage misses. It is not the hour. It is the sudden arrival of darkness in the late afternoon, and the research suggests that matters more for mood than for sleep.
In 2026 the clocks go back on Sunday 25 October in the UK and Europe and on Sunday 1 November in the US and Canada, both at 2am.
What happens when the clocks go back?
At 2am, clocks are set back to 1am. You live that hour twice. In the US this ends daylight saving time and returns to standard time. In the UK it ends British Summer Time and returns to Greenwich Mean Time.
Two things change at once:
- The night gets one hour longer, once.
- Sunrise and sunset both move an hour earlier by the clock, for the rest of the winter. Mornings get lighter for a while. Evenings get dark an hour sooner, on top of the days already shortening.
The first change is small and temporary. The second is large and lasts months.
Do you actually get an extra hour of sleep?
Some people do, at least that first night. But many find the extra hour disappears into the first morning, because the body clock wakes them at the usual biological time, which is now an hour earlier by the clock. Parents of small children and anyone with a dog will recognize this. For a few days, the household is up before the alarm.
Most people's sleep settles within a week. The autumn change is consistently found to be gentler than the spring one. Amneet Sandhu and colleagues (Open Heart, 2014) looked at heart attacks in Michigan hospitals and found a rise on the Monday after the spring change and a reduction on the Tuesday after the autumn one. Losing an hour of sleep is harder on the body than gaining one.
Does your body clock adjust to the clock change?
Not as neatly as the clock does. Thomas Kantermann, Myriam Juda, Martha Merrow and Till Roenneberg analyzed sleep timing in tens of thousands of people in central Europe (Current Biology, 2007). On free days, when people slept on their own schedule, sleep timing tracked the seasonal change in dawn. The clock change did not move the body's timing in the same clean step. It imposed a social schedule on a biological rhythm that had been adjusting gradually.
The mismatch between body time and clock time is what Roenneberg calls social jetlag, and the clock change is a small, forced dose of it twice a year. We wrote about how bodies drift with the seasons in Your Body Changed Seasons. Your Calendar Didn't..
Why the darker evenings matter for mood
The clearest evidence comes from Denmark. Bertel Hansen and colleagues analyzed 185,419 hospital contacts for unipolar depression between 1995 and 2012 (Epidemiology, 2017). The transition from summer time to standard time was associated with an 11% increase in depressive episodes, which faded over about ten weeks. The spring transition showed no matching change.
The authors suggested a plausible explanation. The autumn change moves an hour of daylight from the evening, when most people are awake and outdoors, to the early morning, when many are still asleep. Overnight, it gets dark during the commute home. The sense of the day closing early may be a signal of the coming winter that hits some people hard.
This is a population association, not proof that the clock change causes depression in any individual. But it is a striking signal, and it fits with what is known about light, mood and seasonal depression.
Should we stop changing the clocks?
Many sleep scientists think so, but not in the way most politicians propose. The American Academy of Sleep Medicine's 2020 position statement (Journal of Clinical Sleep Medicine) supports permanent standard time, the time we return to in November. Their reasoning is that standard time better matches clock time to the sun, giving more morning light, which is the strongest signal for setting the body clock.
Permanent daylight saving time, the option that keeps lighter evenings, would mean very dark winter mornings in many places. The US Senate passed the Sunshine Protection Act for permanent daylight saving time in 2022, but it did not become law, and the clocks still change.
How to handle the clocks going back
Keep your wake time steady. Wake at the same clock time the week after the change. A steady morning anchor does more than a lie-in.
Get light early. Go outside within an hour or so of waking, even on a grey day. Outdoor light is many times brighter than indoor light and is the main signal that sets your body clock.
Plan for the dark afternoons. This is the real adjustment. Move a walk to lunchtime. Get outside before it gets dark, not after.
Light the evening warmly, not brightly. Lower, warmer lights after sunset help the body prepare for sleep.
For parents and early wakers: shift bedtime later by 10 to 15 minutes a night in the days before the change, or accept a few early mornings and keep wake time steady.
Watch your mood through November. If you notice the familiar winter slide, start earlier rather than later. Light, movement and social contact help, and persistent low mood should be discussed with a doctor.
Do not treat the extra hour as productivity. It is a rare gift of unscheduled time. Use it for sleep, or for nothing. That is the strategic boredom argument in miniature.
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Related reading: Seasonal Depression vs Burnout · Your Body Changed Seasons · Sleep Anxiety · Relaxation Techniques for Sleep
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Frequently Asked Questions
When do the clocks go back in 2026?
In the UK and most of Europe, the clocks go back one hour at 2am on Sunday 25 October 2026. In the US and Canada, daylight saving time ends at 2am on Sunday 1 November 2026, when clocks fall back one hour to standard time. Arizona, except the Navajo Nation, and Hawaii do not observe daylight saving time.
Do you gain or lose an hour of sleep when the clocks go back?
You gain an hour. When the clocks go back, 2am becomes 1am, so the night is an hour longer. Many people do get some extra sleep that night, although early risers, parents of young children and pet owners often find they simply wake an hour earlier by the clock for a few days.
Does the clock change affect mood?
The autumn change appears to. Bertel Hansen and colleagues analyzed 185,419 hospital contacts for depression in Denmark and found the transition from summer time to standard time was associated with an 11% increase in depressive episodes, which faded over about ten weeks. The researchers suggested the sudden earlier sunset, which shifts darkness into the evening hours when people are awake, may be responsible.
How long does it take to adjust after the clocks go back?
Most people's sleep adjusts within a few days to a week. Research by Thomas Kantermann, Till Roenneberg and colleagues suggests the body clock does not shift neatly with the clock change, so some people feel slightly out of sync for longer. The darker evenings are a separate, longer-lasting change that affects mood for some people through the winter.
Is permanent standard time better than permanent daylight saving time?
The American Academy of Sleep Medicine's 2020 position statement supports permanent standard time, because it keeps clock time closer to the body's natural rhythm and gives more morning light, which is the strongest signal for setting the body clock. Permanent daylight saving time would mean darker winter mornings. The US Senate passed the Sunshine Protection Act for permanent daylight saving time in 2022, but it did not become law.