However, the Observatory’s most enduring legacy is the establishment of Greenwich Mean Time (GMT). In the 19th century, as international trade and travel expanded, it became necessary to ...

To fix this the Royal Observatory decided to set a standard time that everyone could set clocks to. This was called Greenwich Mean time(GMT). GMT became the only official time used in the UK ...

The competition is organized by the Royal Observatory Greenwich in London, England, in association with BBC Sky at Night Magazine, and is open to all ages, and abilities across the globe ...