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British Summer Time: when do the clocks change?

Did you know that the clocks in the UK change twice a year? Check out this handy guide to the changing of the clocks, so that you never lose track of time during your trip to London.

When do the clocks change?

The clocks change twice a year in the UK. They are moved forward by one hour in March, for what is known as British Summer Time, and are turned back by one hour in October.

If you find yourself confused about which way the clocks are moving, remember to use the helpful phrase "spring forward, fall back".

Why do the clocks change?

The changing of the clocks was suggested by William Willett in 1907, who wished to stop the waste of early morning daylight and introduce brighter evenings during the summer months.

British Summer Time was first introduced in 1916 as an Act of Parliament and over the last century the clocks have continued to move forward each year in March, with only a few exceptions, such as during the Second World War.

When do the clocks go forward?

The clocks go forward on the last Sunday of March, jumping from 1am to 2am. When the clocks move forward by an hour, it is known as British Summer Time or Daylight Saving Time.

When do the clocks go back?

The clocks go back on the last Sunday of October, changing from 2am to 1am.

When do the clocks change in 2021/2022?

The clocks will then next go forward by one hour at 1am on 27 March 2022.

The clocks will next turn back by one hour at 2am on 30 October 2022.

What is Greenwich Mean Time?

Greenwich Mean Time is the basis of international time, centered on the Prime Meridian Line at the Royal Observatory Greenwich in London.

If you’d like to learn more about Greenwich Mean Time, don’t miss a visit to the Royal Observatory Greenwich. You can discover the fascinating story of time, see timekeeping artefacts from across the centuries and stand on the Prime Meridian Line, which divides the Eastern and Western Hemispheres.  

What about Big Ben?

Every time the UK moves to British Summer Time, the Great Clock of Westminster in the Elizabeth Tower, commonly known as Big Ben, is carefully adjusted to the new time by the Palace of Westminster Clockmakers during an intricate operation.

Aside from Big Ben, the clockmakers must also update 2,000 other clocks in Westminster over the weekend of the time change.