You got the extra hour and you still woke at six. The kitchen is dark when you come down. It is dark again before you have finished work, and it will be dark at that time until well into the new year. Somewhere in the second week of November you notice you are flattened by four in the afternoon, and nothing has obviously changed to explain it.
Two separate things happen at the end of October, and almost everything written about them runs them together. One is a one hour shift in the clock. The other is the loss of usable evening daylight, which the clock change does not cause and which does not resolve in a few days.
They need different responses. If you have come here looking for something to buy, blue light glasses included, the honest answer arrives later and it is mostly no.
The extra hour is the easy part
Royal Observatory Greenwich has the date: 2am on Sunday 25 October 2026, the last Sunday of the month, as always.
You gain an hour. Your body clock does not know that and wakes you when it was already waking you, which is why the lie-in so rarely materialises. For most adults the mismatch closes within a day or two on its own. Wake at your usual clock time on the Sunday and the Monday, get outside early on both, and that is close to the whole of it.
Most of the advice you will read this month was written for March
Look at the guidance that circulates every October and nearly all of it involves shifting your bedtime gradually across three or four nights beforehand. The protocol is sound. It is written for the spring change.
The Sleep Charity's own clock change guidance shows why. It is titled Spring Forward, it addresses the March change, and it advises going to bed and waking ten to fifteen minutes earlier each day beforehand. That is the right direction when you are about to lose an hour.
In October you are not losing an hour. You are being handed one. A protocol built for a forward shift points the wrong way when the shift is backward, and for most people it solves a problem they did not have.
Their underlying points hold in both directions: morning daylight, a consistent wake time, and not sleeping in to chase the difference.
Who does need to shift something
Some do. The Sleep Charity notes that children, older adults and anyone who already sleeps badly can take several days rather than one. If your child wakes at half five, going back means half four, and a gradual shift in the week beforehand earns its keep. The same holds for a fixed early start on the Monday, or shift work you cannot flex around.
If none of that is you, the taper is optional.
The problem is the light, not the hour
Sunset does not drop an hour on 25 October and then hold steady. It drops an hour and keeps retreating for another eight weeks. The clock change makes the shift abrupt. The seasonal loss of daylight is what carries on, and it is what most people are reacting to by mid-November.
The lever that matters is morning light, and it matters more as the mornings darken. Getting outside in the first hour or two after waking, even under heavy cloud, is the strongest anchor a body clock has. A dull British November morning delivers far more light than any indoor room with the lamps on.
Evening light pushes the other way, and here the research is solid. Chang and colleagues, in PNAS in 2015, ran a two week inpatient study: participants read either a light-emitting device or a printed book for four hours before bed. The device suppressed evening melatonin by around 55 per cent, delayed sleep onset, and left people less alert the next morning.
Worth being specific about what that shows. It had twelve participants. It used four hours of close-range screen exposure in a controlled unit, heavier than most evenings look. It establishes that evening light delays the body clock. It does not tell you how much difference an hour on your phone makes to your particular Tuesday.
What about blue light glasses
This is the obvious thing to reach for, and it is the weakest link in the chain.
Blue light glasses filter part of the short wavelength range, roughly 380 to 500 nanometres. That is the mechanism, and it is real. What has not held up is the step from there to better sleep.
A Cochrane review published in 2023 pooled seventeen randomised trials covering 619 participants and found the evidence insufficient and inconsistent. No convincing sleep benefit. That is where it sits, and it is not a close call.
Which leaves an honest position rather than a comfortable one. The evening light effect is well evidenced. The product sold on the back of it is not. If you want a pair for screen glare or eye comfort, that is a reasonable thing to want, and a different reason from the one they are usually sold on. Look for them on that basis if you like. Do not buy them expecting them to fix late October.
Dimming the room and putting the phone down earlier costs nothing and rests on better evidence.
When the dark is more than an inconvenience
For some people winter is not a fortnight of feeling flat.
Seasonal affective disorder is a form of depression that usually arrives in winter, and the NHS describes it as thought to be linked to reduced daylight. Low mood, losing interest in things you normally enjoy, difficulty concentrating and sleeping more than usual are among the signs it lists. See a GP if you think you might have it, or if what you are already doing is not helping.
That is a GP conversation, not a shopping one. Nothing sold here is an alternative to it.
On light boxes, sometimes sold as SAD lamps, the NHS is more cautious than the marketing. They are not usually available on the NHS because there is not enough evidence to say whether they work, though many people report finding them useful. Speak to a GP first, since they may not suit certain eye conditions or medicines that increase light sensitivity. If you buy one, the NHS says look for 10,000 lux, UV-free, and a UKCA or CE mark.
Separately, if you have been sleeping badly three or more nights a week for three months or longer, that is long-term insomnia rather than a seasonal wobble, and it is worth raising with a GP whatever the clocks are doing.
The short version
The hour is not really your problem. Wake at your usual time on the Sunday, get outside early, and it sorts itself out inside two days. If you have small children or a fixed early start, shift gradually in the week beforehand.
The light is your problem, and it is a two month one rather than a two day one. Morning daylight does the work. A dimmer evening helps. The glasses, on the current evidence, do not.
For the fuller version of holding a routine through a dark winter, our guide to building a pre-sleep routine is the place to start.
Driftward exists because most of the answers in this category get sold before they get tested. You can read why we started if you are curious.
Frequently asked questions
When do the clocks go back in 2026?
At 2am on Sunday 25 October 2026, on the last Sunday of October, as they do every year. You gain an hour and the UK returns to Greenwich Mean Time.
How long does it take to adjust when the clocks go back?
For most adults, a day or two. The autumn change is the easier of the two because you gain an hour rather than lose one. The Sleep Charity notes that children, older adults and people who already sleep badly may take several days.
Should I change my bedtime before the clocks go back?
Most people do not need to. The gradual shift you will see recommended is written for the spring change, when an hour is lost. It is worth doing in October if you have a young child who already wakes early, a fixed early start on the Monday, or shift work you cannot flex around.
Do blue light glasses help you adjust to the clocks going back?
There is no convincing evidence that they improve sleep. A 2023 Cochrane review of seventeen randomised trials covering 619 participants found the evidence insufficient and inconsistent. Evening light does delay the body clock, but that is a reason to dim the room rather than a reason to buy glasses.
Why do I feel worse in November than I did in October?
Because the clock change is not the whole story. Daylight keeps shrinking for weeks afterwards, so the shorter afternoons continue long after the hour has been absorbed. If low mood lasts, is affecting daily life, or returns at the same point each winter, that is worth speaking to a GP about.