British summer time

During British Summer Time (BST), civil time in the United Kingdom is advanced one hour forward of Greenwich Mean Time (GMT) (in effect, changing the time zone from UTC+0 to UTC+1), so that evenings have more daylight and mornings have less.

BST begins at 01:00 GMT on the last Sunday of March and ends at 01:00 GMT (02:00 BST) on the last Sunday of October. Since 22 October 1995 the starting and finishing times of daylight saving time across the European Union have been aligned – for instance Central European Summer Time begins and ends on the same Sundays at exactly the same time (that is, 02:00 CET, which is 01:00 GMT). Between 1972 and 1995, BST began and ended at 02:00 GMT on the third Sunday in March (or second Sunday when Easter fell on the third) and fourth Sunday in October.

The following table lists recent past and near future starting and ending dates of British Summer Time:

British Summer Time was first established by the Summer Time Act 1916, after a campaign by builder William Willett. His original proposal was to move the clocks forward by 80 minutes, in 20-minute weekly steps on Sundays in April and by the reverse procedure in September. In 1916 BST began on 21 May and ended on 1 October. Willett never got to see his idea implemented as he died in early 1915.

In 1940, during the Second World War, the clocks in Britain were not put back by an hour at the end of summer. In subsequent years, clocks continued to be advanced by one hour each spring and put back by an hour each autumn until July 1945. During these summers, therefore, Britain was two hours ahead of GMT and operating on British Double Summer Time (BDST). The clocks were brought back in line with GMT at the end of summer in 1945. In 1947, due to severe fuel shortages, clocks were advanced by one hour on two occasions during the spring, and put back by one hour on two occasions during the autumn, meaning that Britain was back on BDST during that summer.

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