Home of time

Find out how the Royal Observatory became the home of Greenwich Mean Time (GMT) and the first state-funded scientific institution of its day. Stand on the historic Prime Meridian of the world, where East meets West, see John Harrison's groundbreaking timekeepers up close, and explore the home of the Astronomer Royals.

Stand on the historic Prime Meridian of the World and see John Harrison's legendary timekeepers

Stand on the Prime Meridian Line
Stand on the Prime Meridian at Royal Observatory Greenwich

What is GMT and why is it so important?

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Discover John Harrison's iconic marine timekeepers
Harrison's marine timekeeper H4

When do the clocks go forward?

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Explore the Time and Longitude gallery
John Harrison's marine timekeeper H1 three quarter raised view from front right
Why do we have British Summer Time?
Shepherd Gate Clock

Dolphin dial

Image of the Dolphin dial at the Royal Observatory
Come to our talks and courses