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 times of commencement and cessation 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.

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