What is Daylight Saving Time?

Daylight saving time (DST) or, more commonly known as ‘British Summer Time’ here in the UK, is the period between the end of March and the end of October when we move our clocks forward by one hour. In March, we ‘spring forward’ to British Summer Time by setting our clocks ahead. On the last Sunday of October, we "fall back" to standard Greenwich Mean Time (GMT) by putting our clocks back.

Similar to jet lag, a time change like this can interfere with our body's sleep-and-wake cycles. It can cause sleep loss in the short term, and some health experts believe the effects can last longer.

Why do we have British Summer Time?

The idea behind British Summer Time is to gain more sunlight in the evening during late Spring, Summer and early Autumn. It was first mentioned in 1784 by Benjamin Franklin, the American inventor, scientist and statesman. However, it wasn’t until 1907 that William Willet, a British inventor and builder, made a serious proposal for moving the clocks forward by one hour from Greenwich Mean Time (GMT) in Summer. However, the change didn’t happen until 1916, when Germany first adopted this practice during World War 1, as a temporary effort to save on energy and this was quickly followed by the UK and then other European countries.

During World War 2, British Double Summer Time – two hours in advance of GMT – was introduced and remained one hour in advance of GMT for the winter, as this was to increase productivity. When the war ended, Britain returned to British Summer Time and other than three years between 1968 and 1971 when, as an experiment, the clocks were not changed back one hour from British Summer Time, clocks have continued to go forward at the end of March and go back at the end of October.

What are the effects of time change?

Changing your daily schedule can disrupt your circadian rhythm, which is controlled by the sleep hormone, melatonin. Your circadian rhythm is your body's natural 24-hour cycle, which is strongly influenced by light. Light keeps your body from releasing melatonin, a hormone that promotes sleep.

This disruption can cause you to lose sleep, which not only makes you feel fatigued and grumpy, which, in turn, can affect your mental sharpness and productivity. Losing just an hour of sleep can throw off your internal clock for several days or more.

You may be more prone to these effects if you work a night shift or otherwise tend to wake up later in the day, or if you're a teenager. The time change can also be upsetting to people with Alzheimer's and other types of dementia.

Is it harder to adjust to the ‘Spring Forward’ time change?

Experts agree that it's harder for our body clocks to ‘spring forward’ into British Summer Time than to "fall back" to standard time. One reason is that many of us lose an hour of sleep on the night of the transition.

Another is that, with the change to British Summer Time, those on typical work or school schedules are exposed to less light in the morning and more at night. This may lead to later bedtimes, which can result in long-lasting sleep deficits.

When do we move the clocks forward?

In the UK, daylight saving (moving our clocks forward by one hour) happens at 2am on the last Sunday in March. In 2025, this is Sunday, 30th March.

Spring forward sleep tips

Use these tips to help you spring forward easily and sleep better all year long:

Transition gradually: Start going to bed 15 minutes early several days before the change. Make an extra effort to be well-rested the week before the time change.
Seek sunshine: The morning after British Summer Time begins, step outside and catch some rays soon after you wake up. Sunlight helps to reset your body’s internal clock.
Take a sleep break: If you feel sleepy after the change to British Summer Time, take a short nap in the afternoon -- but not too close to bedtime. Avoid sleeping in longer in the mornings. Your internal clock should adjust in several days.
Pace yourself: Try not to jam-pack your schedule right after the time change. Tackle important to-dos, like work presentations, later in the week if you can.
Drive safely: Be extra careful behind the wheel. Save that long-distance road trip for when you’re fully alert to lower your chances of getting into a car accident.
Know how much sleep you need: Not everyone needs the same amount of sleep to be well-rested, and sleep requirements can change with age. To find your ideal number of hours, sleep without an alarm on weekends and see when you wake up naturally.
Keep regular sleep hours: Once you are settled into British Summer Time, try to go to bed and wake up at the same time each day, including weekends, to help your body regulate its sleep pattern. Be aware of how napping affects your sleep quality. For some, a nap makes nighttime sleeping harder; but for others, a short nap (20 minutes) can be revitalising without ruining their night's sleep.
Get some exercise: Even gentle exercise, such as stroll, can help you sleep better. Aim for at least 30 minutes of moderate movement, three times a week or more. If you often sleep poorly, don't exercise too close to bedtime.
Avoid stimulating substances: Alcohol and caffeine can interfere with sleep. If you have trouble sleeping, avoid alcohol and caffeine for 4 to 6 hours before bedtime. Smokers should avoid tobacco, another stimulant, too close to bedtime.
Eat lightly at night: Indigestion from spicy or fatty food, or just having too much food in your stomach, can keep you awake. For a better night's sleep, eat light, simple foods several hours before bed. If you get hungry, have an easy-to-digest snack such as carbohydrates or dairy. Avoid drinking too much liquid before bed so that you don't keep waking up to go to the bathroom. Check out our food tips to help better sleep.
Relax before bed: Stress and overstimulation make it hard to fall asleep. Avoid intense TV programs or movies before bed. Relax with a warm bath and curl up with a book instead. If anxiety keeps you awake, write out your schedule for the next day before going to bed, including possible solutions to any challenges you're facing. If you're worried about hitting a deadline, get up early to work instead of working late into the night. Meditation can also help you to relax before bedtime.
Create a calm, sleep-friendly environment: Try sleep shades, earplugs, or blackout curtains – or all of them! Temperature helps, too: 16 - 18 degrees is usually the optimal temperature for sleep. Even your bedroom colour scheme can help create a more restful environment. If you have restless or snoring pets, keep them out of your room, along with all electronics, including your phone and TV.
Select breathable bedding: Wool is naturally breathable, temperature regulating and dust mite resistant, so creates an optimal bedding environment. Studies have shown that wool also helps to achieve a more restful sleep whilst it helps to keep your core body temperature balanced throughout the night. Find out more about our award-winning, individually handcrafted wool bedding. Make sure you sleep in PJs or a nightie made with 100% natural fibres, such as cotton.
Don't lie awake: If you can't fall asleep, or if you wake up and can't get back to sleep, don't watch the clock. This only creates more anxiety. If you're awake for more than 20 minutes, get up, go to another room and do something relaxing. Keep the lights low, have some warm milk, read a book, or write about whatever is on your mind until your eyelids get heavy.
Avoid sleep aids: Taking melatonin supplements at night could make you sleepy during the day. Some prescription sleeping pills can also make you less alert and can be addictive. Talk to your doctor before you try any sleep aid to learn about possible side effects and make sure it doesn’t interact with other meds you may already be taking.

Ref: Royal Museums Greenwich, Sleep Foundation, Serious Readers