The history of British Summer Time

  • Published
  • 100th Air Refueling Wing
Don't forget to Change your clocks this weekend and "Spring Forward" one hour on Sunday March 25 at 1 a.m. Greenwich Mean Time 

It has been 100 years since British Summer Time was first proposed. But why change the clocks, which way and whose idea was it? 

History of legal time in Britain
Before the railways, local mean time was the time kept by clocks and used for general purposes in the UK, in so far as people kept time by clocks rather than by the sun. (Mean time, as shown by sufficiently accurate clocks, had largely replaced apparent time, as shown by a sundial, from around the end of the eighteenth century.) 

With the coming of the railways, it became a significant problem for timetables that the time at one end of a railway line should differ significantly from that at the other. For this reason, in the 1840s the railway companies started to keep London time consistently at their stations and on their trains. 

It was recommended by the Railway Clearing House that all the railway companies should adopt Greenwich time in September, 1847, and by January 1848 this had generally been done. Over the next few years the rest of the country followed the railways, but in the 1858 case of Curtis v. March it was ruled that the time for legal purposes must be considered to be local mean time. 

In 1880 the legal time for Great Britain was made Greenwich mean time by Act of Parliament; that for Ireland was made Dublin mean time. For a more detailed history of events up to this point, see Derek Howse, Greenwich Time and the Longitude (National Maritime Museum / Philip Wilson 

The institution of Summer Time, advances the legal time by one hour during the summer months in order to promote greater efficiency in the use of the daylight hours and of artificial lighting. This was originally introduced as a wartime measure in 1916 and has been continued through peacetime. 

Occasional variations such as double summer time (advancing the clocks by a second hour for part of the summer) in World War II - the government files on which in the Public Record Office (now National Archives) having, when the closure period was first set (probably late 1960s), been deemed so sensitive as to merit a closure period of 100 years - and the experiment with British Standard Time from 1968 to 1972, by which the time was advanced by one hour from GMT throughout the year. 

Adjusting the clocks has been an extremely effective way of really changing the times at which most people work (as measured on a uniform time scale).
Maritime Greenwich 

You can visit the world heritage site at Greenwich, the home of historic landmarks such as the Cutty Sark, the last surviving tea clipper, and the Royal Observatory, the home of Greenwich Mean Time and the Meridian Line, Longitude 0°. 

So near to central London yet remote from the hustle and bustle of the city centre, Greenwich is a place of contrasts, from awe-inspiring architecture, tranquil open spaces and breathtaking views to cosy pubs and bustling street markets.
For more information - please see http://www.greenwichwhs.org.uk/