British Summer Time and Greenwich Mean Time

British Summer Time (BST) — when clocks are moved backward one hour — runs from the last Sunday in March to the last Sunday in October.

On the last Sunday in October, clocks are moved forward an hour and Greenwich Mean Time (GMT) begins.

GMT means that London loses an hour of daylight…and winter has at last returned. 

If you want to know more about time and how it came to be measured, astronomy and/or navigation, visit the Royal Observatory at Greenwich. The Observatory, home to the 0-degrees-longitude Greenwich Meridian Line (which you can step over to experience time travel), also houses excellent exhibitions of clocks, timepieces and telescopes. Here you’ll find interactive exhibits on astronomy and navigational tools, along with the stories of the people who pioneered these disciplines.