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 Central European Time, which is 01:00 GMT). Between 1972 and 1995, the BST period was defined as "beginning at two o'clock, Greenwich mean time, in the morning of the day after the third Saturday in March or, if that day is Easter Day, the day after the second Saturday in March, and ending at two o'clock, Greenwich mean time, in the morning of the day after the fourth Saturday in October."
The following table lists recent-past and near-future start and end 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 lived to see his idea implemented, having died in early 1915.