Discover everything there is to know about the story of time, from the relationship between Greenwich and time to the people responsible for inventing groundbreaking, timekeeping instruments.
Visit the Home of Time
Discover how the Royal Observatory revolutionised the recording of world time, stand astride the Prime Meridian Line – the historic place where east meets west – and have a peek inside the Great Equatorial Telescope
What is Greenwich Mean Time?
Everything you need to know about the historic international standard of civil time
Who has the time?
Our experts delve into the history of time – and reveal Greenwich's relationship with time
The history of timekeeping
Explore the evolution of time telling – and the treasures within our horological collections
Our collections: A unique history of timekeeping
Our collection of approximately 1000 horological objects covering marine, astronomical and domestic timekeeping
Sundials
For thousands of years, the sundial has told the time and divided the day.
Which time is it?
Next time someone asks you the time, you may enquire if they want to know the atomic, universal, civil, local, solar or sidereal time
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 do we change the clocks?
Learn about the history of British Summer Time (BST) and Daylight Saving Time
When do the clocks go forward in 2025?
Marking the start of British Summer Time, the clocks 'spring forward' in March, meaning we'll lose an hour's sleep
British Summer Time (BST) and Daylight Saving - understanding UK time changes
Why does UK time change, and when was British Summer Time first introduced? Explore the history of BST and daylight saving
The clocks that changed the world
Discover how John Harrison's clocks helped to solve one of seafaring's greatest problems: finding longitude
Clock themed books and gifts
