What does BDST stand for? 

BdSt

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±00:00 to UTC+01:00, so that mornings have one hour less daylight, and evenings one hour more.BST begins at 01:00 GMT every year on the last Sunday of March and ends at 01:00 GMT (02:00 BST) on the last Sunday of October. The starting and finishing times of daylight saving were aligned across the European Union on 22 October 1995, and the UK retained this alignment after it left the EU; both BST and Central European Summer Time begin and end on the same Sundays at 02:00 Central European Time, 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:

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