Greenwich Mean Time

This is the time used in the United Kingdom in winter.

Greenwich Mean Time is exactly one hour behind British Summer Time. For example, when it is 10:00 Greenwich Mean Time, it is 11:00 British Summer Time.

Clocks in the United Kingdom are turned back one hour on the last Sunday in October and move from British Summer Time to Greenwich Mean Time.

If we use a clock which follows Greenwich Mean Time, the sun reaches its highest point in the sky at midday in the Royal Observatory Greenwich, London.