British Summer Time (BST)
At 1.00 am GMT (or UTC) on Sunday 31 March 2013, clocks in the UK go forward one hour for the start of British Summer Time (BST). At this point, civil time officially changes from Coordinated Universal Time (UTC, effectively the same as Greenwich Mean Time) to BST.
The Ninth European Parliament and Council Directive on Summer Time Arrangements states that summer (or daylight saving) time will be kept between the last Sunday in March to the last Sunday in October. The changes will take place at 01.00 GMT.
|2010||28 March to 31 October|
|2011||27 March to 30 October|
|2012||25 March to 28 October|
|2013||31 March to 27 October|
|2014||30 March to 26 October|
|2015||29 March to 25 October|
|2016||27 March to 30 October|
2007 marked 100 years since British Summer Time was first proposed. But why change the clocks, which way and whose idea was it? Find out in our Spring Forward pages.
- David Rooney discovers more about British Summer Time
- David Rooney introduces St. John Wynne
- David Rooney reveals the story of Ruth Belville
- David Rooney visits the Daylight Inn
- See all our time and timekeeping fact files, including leap seconds, calendars, equinoxes and solstices and the equation of time.
- Read our FAQs about time, including 'Is noon 12 am or 12 pm?' and 'Why isn't the earliest sunrise on the longest day?'
- Download Calendars from around the world, an in-depth look at the different calendars used throughout history and those still in use today.
- View the new Time galleries at the Royal Observatory.
- Buy clocks and watches online from the Museum.
The idea of summer time, or daylight saving time, was first suggested in a whimsical article by Benjamin Franklin in 1784. In 1907 an Englishman, William Willett campaigned to advance clocks by 80 minutes, by 4 moves of 20 minutes at the beginning of the spring and summer months and to return to Greenwich Mean Time (GMT) in a similar manner in the autumn. In 1908 the House of Commons rejected a Bill to advance the clocks by one hour during the spring and summer months.
Summer time was first defined in an Act of 1916 that ordained that for a certain period during the year legal time should be one hour in advance of GMT. The Summer Time Acts of 1922 to 1925 extended the period during which summer time was in force and so, from 1916 up to the Second World War, clocks were put in advance of GMT by one hour from the spring to the autumn.
During the Second World War, double summer time (2 hours in advance of GMT) was introduced and was used for the period when, normally ordinary summer time would have been in force. During the winter clocks were kept one hour in advance of GMT. After the war, summer time was invoked each year from 1948 to 1967. In 1968 clocks were advanced one hour ahead of GMT on 18 February and remained so until British Standard Time, during which clocks were kept in advance of GMT all year, came into force between 27 October 1968 and 31 October 1971.
The Summer Time Act 1972 defined the period of British Summer Time to start at 02.00 GMT on the morning of the day after the third Saturday in March or, if that was Easter Day, the day after the second Saturday. It was to end at 02.00 GMT on the day after the fourth Saturday in October. The duration of British Summer Time can be varied by Order of Council and in recent years has been changed so as to bring the date of the start of Summer Time into line with that used in Europe. (In the 1980s the European Community started issuing directives which required member states to legislate specific start and end dates for summer time in order to improve coordination of transport and communications.)
The rule for 1981–1994 defined the start of summer time in the UK as the last Sunday in March and the end as the day following the fourth Saturday in October. The time of change was altered to 01.00 GMT.
There was no rule for the dates of summer time for the years 1995, 1996 and 1997, but the ad-hoc dates were:
|1995||26 March to 22 October|
|1996||31 March to 27 October|
|1997||30 March to 26 October|
|all changes taking place at 01.00 GMT|
In 1998 the end date was adjusted to be the last Sunday in October; the ninth directive, currently in force, has made this permanent. According to this directive, summer (or daylight saving) time will be kept between the last Sunday in March to the last Sunday in October, all changes taking place at 01.00 GMT.
Some people advocate that summer time is kept all year round but this is opposed by other groups on the grounds that in the north this would have social disadvantages including, for instance, the problem that in the far north-west of Scotland sunrise would occur at about 10.00 in the middle of winter and over much of the north small children would have to travel to/from school in darkness.
Many countries around the world use daylight saving time, including the USA, Russia, most of Europe and the Commonwealth.
The main reasons given for the use of summer time are the saving in power given by the longer hours of daylight in the evenings and the increased useful daylight leisure time available to those who work.