Clocks and timekeeping

Read all about the history of timekeeping and the amazing instruments in Royal Observatory Greenwich's collection

When do the clocks go back?

Marking the end of British Summer Time, the clocks go back in October, giving us an extra hour in bed

The lost chronometer: the timepiece that sailed with Charles Darwin and Sir John Franklin

Learn more about the marine chronometer that journeyed on board HMS Beagle before being lost at sea during Sir John Franklin's disastrous expedition

Time before Greenwich Mean Time: the confusing case of the traveller's watch

Before time became standardised, different areas of the country all kept their own 'local time'. This gold traveller's watch with two minute hands shows how tricky that could be

The BBC pips: the Royal Observatory and the Greenwich Time Service

Discover the story behind the Greenwich time pips, first broadcast by the BBC over 100 years ago in 1924

What is a nocturnal?

Learn more about the nocturnal or ‘nocturlabe’, used for centuries to tell the time based on the movement of the stars

The Greenwich Time Lady: Ruth Belville

Discover the story behind the media sensation Ruth Belville, who brought the correct time from the Royal Observatory to London for almost 50 years.

When do the clocks go forward?

Marking the start of British Summer Time, the clocks 'spring forward' in March, meaning we'll lose an hour's sleep

Which years are leap years and can you have leap seconds?

Because the Earth takes a little over 365 days to orbit the Sun, we need to make adjustments to keep the seasons from drifting: leap years and even leap seconds

Why 12 months in a year, seven days in a week or 60 minutes in an hour?

While days and years are (fairly) neat astronomical events, what explains months, weeks, hours and minutes?