When Do The Clocks Go Back? 10 Things You Might Not Know

6 min read

Last Modified 25 October 2021 First Added 18 September 2020

By Leigh Horan

It’s that time of year again when we ask “when do the clocks go back?” and try to make the most of the daylight hours during the winter season. The change of the clocks often results in a state of confusion for the majority of the country, as we lose or gain an hour throughout the course of the year. But why do we change the clocks anyway? Before we find out, let’s answer the most important questions first:

When do the clocks go back?

Sunday 31st October 2021. The clocks always go back on the last Sunday of October in the UK, which this year (2021), falls on the 31st.

What time do the clocks go back?

The clocks go back at 02:00 on Sunday morning, 31st October 2021.

Do we get an extra hour of sleep?

Yes! The change in October is “the good one” where we get an extra hour in bed on the Sunday morning of the change. This is due to the clocks going back, which means you gain an hour. It is in spring that you lose an hour when the clocks change.

Now that we’ve sorted that, here are some little-known facts about this annual ritual:

1. Why do the clocks change?

It was William Willett’s idea to change the clocks.

The proposal for Daylight Savings Time was put forward by William Willett in 1907, as he argued that we were wasting important daylight by rising at the same time in the summer as we did throughout the winter months. He believed we should advance our clocks by 80 minutes via four incremental sets of 20 minutes during April. This would then be reversed in the same fashion during September.

Related: The Daylight Savings Hub

2. When did the clocks first go back?

The clocks first changed in 1916 in the UK. However, though Willett proposed this in 1907, Britain failed to adopt the idea until 1916, a month after Germany had taken up the idea. The idea was particularly attractive at this time as the First World War was taking its toll on the nation, and anything that could improve productivity was encouraged.

man changing clock for end of daylight savings

Related: What Happens To Your Body During 8 Hours Of Sleep?

3. Benjamin Franklin joked about changing the clocks back in 1784

Daylight Savings Time was first satirically proposed by Benjamin Franklin in a letter he addressed to Parisians in 1784. His argument was that more daylight would mean people wouldn’t waste candles by having to burn them for longer.

4. Retailers rely on Christmas to offset the clock change

Retailers dislike the change to GMT as the darker evenings mean that much fewer people are likely to go shopping in the evenings after work. Obviously, any damage done is offset by the manic Christmas period, but with both opening and closing occurring in the dark, it can seem like a long time before the clocks change again!

5. Why do clocks change on a Sunday?

Clocks change on a Sunday thanks to the EU. Daylight Savings Time is always kept between the last Sunday of March and the last Sunday of October, and all changes take place at 01:00 GMT as according to an EU directive.

Image of a tractor to show how the clocks going back helps farming and produce industries

6. Changing the time helped coal supply during World War One

The main reason for turning the clocks back was to make the most of the daylight available in the summer. Another argument, however, was that the different hours would affect the amount of domestic coal usage, thereby increasing the supplies available for manufacture and for supporting WWI.

7. Dairy farmers in the North like changing the time most

There are many other reasons why we change our clocks twice during the year. Agriculture is a major concern, with farmers working hours being more affected by the amount of daylight available in the morning than the rest of us. Farmers often rise or begin work at around 5 in the morning. If the clocks were not adjusted, dairy farmers located in the North of the country would not see dawn until after 9 o’clock, meaning hours of working in the dark.

8. Spring forward, fall back

Next time you’re thinking “when do the clocks go back?” simply memorise the phrase “spring forward, fall back”. The clocks always spring forward an hour on the last weekend in March and fall back on the final weekend of October.

Image of autumnal walk

9. Clocks go back around the world

Only around a quarter of countries in the world have any type of clock change at all and these don’t necessarily occur on the same schedule. Not even all the U.S states operate on the same schedule, with parts of Arizona, Hawaii, Puerto Rico, the U.S Virgin Islands and American Samoa declining to follow suit.

10. Is it darker in the morning when clocks go back?

It’s going to get dark, very dark during, but putting the clocks back helps us to utilise the daylight in the morning. At the height of summer, on the summer solstice, the UK enjoys a hefty 16 hours and 50 minutes of sunlight. However, that is going to shrink to a measly 7 hours and 40 minutes on the winter solstice. Putting the clocks back helps us take advantage of the little daylight we get. Find out more about the dates clocks change here.

What is the effect of putting the clocks back?

Setting the clocks back by an hour at the end of October means the mornings are lighter, which can have an effect on the time you wake up in the morning. To make sure you’re getting sufficient rest, make sure your bedroom will be dark enough for you to achieve your full 8 hours.

Related: How to Get Out of Bed in the Morning When You Don’t Want To

Wake and sleep time are the major effect that the clocks changing can have, with many struggling to get enough rest. One study suggested a spike in reported heart attacks in the week after clocks go forward, possibly due to sleep loss. To ensure you have the best chance of getting a good night’s sleep, consider altering your bedtime by ten minutes over a few days in anticipation of the change.

image shows a clock and woman sleeping to identify how clocks going back affects sleep

You should also continue to practise good sleeping habits, by avoiding screens a good hour before bedtime, avoiding caffeine and other stimulants and making sure you have a comfortable sleeping environment in which to spend your extra hour of sleep.

Remember: the UK reverts to GMT on the last Sunday in October, which means an extra hour in bed for us all!

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