The Story of BST













BST in 2002 and beyond
British Summer Time is determined by an Act of Parliament: the Summer Time Act, 1972. This Act enables an Order in Council to specify exactly when the changes will occur. Such "Summer Time Orders" have, in the past, usually defined BST for the following three or four years (for instance, the Summer Time Order, 1997, which gave the dates for 1998, 1999, 2000 and 2001).

However, since the Summer Time Order, 1994 (that is, in 1994 and 1997) the dates have been those determined by the EC directive on daylight saving, thus formally synchronised our summer time changes with Europe (which is the last Sunday in March and the last Sunday in October).

In theory, there should have been a new Summer Time Order, 2001, to formally fix the dates for the 2002 onwards - but it didn't happen. Instead, the Government left it until very late to issue the Summer Time Order, 2002, which wasn't laid before Parliament until towards the end of February, 2002, and came into force on 11st March, 2002.

The big difference is that the 2002 Order repeals both the ability of the 1972 Act to vary British Summer Time and the ability to introduce Double Summer Time. It formally adopts the EC Directive and gives the formula:

(2) The period of summer time for the purposes of this Act is the period beginning at one o'clock, Greenwich mean time, in the morning of the last Sunday in March and ending at one o'clock, Greenwich mean time, in the morning of the last Sunday in October.

So, no longer will we need to wait for an Order to determine the start/end of BST, much to the relief of diary publishers.

Where did it all start?
Benjamin Franklin was the first to propose the idea of adjusting the clocks, perhaps less than seriously, in an essay in 1784. But it was William Willett who, in 1907, started the campaign to move the clocks forward for the lighter and warmer months. His original suggestion was to move the clock forward 20 minutes at a time in the spring, and then 20 minutes at a time backwards in the autumn.

A modified version of his idea (an hour change in spring and autumn) was proposed in the House of Commons in the following year, but was rejected.

It wasn't until World War I that the case became convincing. In 1916, the UK adopted "daylight saving time" through the Summer Time Act, 1916, and the measure proved successful in reducing the demand for coal, despite farmers' objections.

In total there have only been five Acts of Parliament allowing and defining BST: 1916, 1922, 1925, 1947 and 1972. All other changes have been done through Orders In Council (Summer Time Orders), which either changed the rules or the dates. However, in 1939, under the Emergency Powers (Defence) Act, 1939, the Defence (Summer Time) Regulations, 1939 was issued to amend the 1925 Act, which then took over again in 1946.

The dates for changing to and from British Summer Time are either given explicitly, or the various Acts and Orders define a rule.

In addition, since 1981, the EC has had its own directive on Summer Time. But Europe did not fully synchronise the changes until 1996 (the UK adopted the European directive in 1994).

When the USA saw the success of Summer Time, they introduced their own legislation in 1918. However, it was a bit of a hit-or-miss affair and, in 1966 the Uniform Time Act was enacted which defined the start and end of daylight saving time. Any state could pass a law exempting it, but if so, it had to adhere to the federally-defined dates.

From 1987, the US changed at 2am on the first Sunday in April, and reverted at 2am on the last Sunday in October. However, in an experiment to try to reduce energy consumption, Daylight Saving Time was extended by a month from 2007. So it now starts on the second Sunday in March and ends on the first Sunday in November.

The only US states that do not observe it are Arizona, Hawaii and some counties in Indiana (which itself is the only state to actual straddle two time zones, which means that times in Indiana can range over three house). And ub Arizona, although the state itself does not observe daylight saving time, Navajo reservations do - and that can become very confusing!

Further information is on my US Daylight Saving Time page.

The timescale
I've prepared a table showing the details of all changes since BST was introduced, together with the time the changes would occur and the resulting time relative to GMT.