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Time Zone History of the United Kingdom

The United Kingdom started using Greenwich Mean Time (GMT) as its standard time in 1880. It remained the base of civil time in the world until 1972.

The Shepherd Gate Clock on the wall at the Royal Observatory Greenwich.

The Shepherd Gate Clock showed GMT first.


The United Kingdom was among the first countries to use a standard time for the whole country, replacing the practice of each place keeping its own local mean time.

“Railway Time”

With the introduction of the railway, travel became faster. With every station keeping its own local mean time, the need for a synchronized time arose.

The first railway company to implement a common time for all stations, appropriately named “Railway Time,” was the Great Western Railway in November 1840. By 1847, most railways were using “London Time,” the time set at the Royal Observatory in Greenwich.

In 1847, the Railway Clearing House, an industry standards body, recommended that Greenwich Mean Time (GMT) be adopted at all stations as soon as the General Post Office permitted it. On December 1, 1847, the London and North Western Railway, as well as the Caledonian Railway, adopted “London Time,” and by 1848 most railways had followed.

Unofficial GMT

By 1844, almost all towns and cities in Britain had adopted GMT, though the time standard received some resistance, with railway stations keeping local mean time and showing “London Time” with an additional minute hand on the clock.

In 1862, the Great Clock of Westminster, popularly known as Big Ben, was installed. Though not controlled by the Royal Observatory at Greenwich, it received hourly time signals from Greenwich and returned signals twice daily.

Standard Time Adopted

However, it was not until 1880 that the British legal system caught up with the rest of the country. It had stuck to local mean time for years, leading to oddities such as polls opening at 08:13 (8:13 am) and closing at 16:13 (4:13 pm) during some elections.

With the Statutes (Definition of Time) Act (43 & 44 Vict.), Greenwich Mean Time was legally adopted throughout the island of Great Britain on August 2, 1880. Ireland replaced Dublin Mean Time with GMT in 1916.

GMT World Standard

In 1884 GMT was adopted as the international standard for civil time at the International Meridian Conference in Washington, D.C., USA. It remained the standard until 1972 when it was replaced with Coordinated Universal Time (UTC).

UTC is still primarily based on the solar time on the prime meridian (0° longitude) near the Royal Observatory in Greenwich.

British Summer Time (BST)

The English have not only pioneered standard time. It was also an Englishman who was responsible for the invention of Daylight Saving Time (DST), or summer time, as it is commonly known as in the UK.

In 1907, English builder William Willett published a pamphlet called The Waste of Daylight, campaigning to advance clocks at the beginning of the spring and summer months and to return to GMT in the autumn. He wanted to encourage people to get out of bed earlier in summer.

Willett spent the rest of his life fighting for his time-shifting scheme but died of influenza before DST was implemented.

Rejected Bill

The 1908 Daylight Saving Bill was the 1st attempt in the UK to move clocks forward 1 hour in summer. The idea was to provide more daylight hours after work for the training of the Territorial Army, to reduce railway accidents, and to reduce lighting expenses. The House of Commons rejected the Bill.

However, across the Atlantic a British colony in Canada made history. On July 1, 1908, the residents of Port Arthur, Ontario, today's Thunder Bay, turned their clocks forward by 1 hour to start the world's first DST period.

Wartime Energy Saver

In 1916, during World War I, Germany was the 1st country in the world to use DST nationwide, and the UK followed just weeks later. To save energy and help the war effort, the Summer Time Act 1916 advanced the clocks in the UK for 1 hour from May 21 until October 1 in the same year.

Summer time, or DST, proved so popular that it was named British Summer Time (BST) and the seasonal practice kept.

“British Double Summer Time”

There have been periods in UK history where DST was 2 hours ahead of standard time. This is known as “British Double Summer Time” (BDST), “Double Summer Time,” or “Double British Summer Time.”

During World War II the UK went on an extended DST period from February 25, 1940 to October 7, 1945, effectively adding 1 hour to the time zone (UTC+1). During the DST period in the summer, another hour was added to the time zone (UTC+2).

There was another period of BDST in 1947, which was brought on by severe fuel shortages in the country.

3 Years of Summer Time

In a trial known as the British Standard Time experiment, the UK kept Daylight Saving Time hours permanently from February 1968 to November 1971. Although the experiment resulted in fewer traffic incidents because darkness fell 1 hour later on the clock, it was found that there was a slight increase in incidents in the darker morning hours. The experiment was abandoned in 1972 because of its unpopularity—particularly in the north of the country, where days are generally shorter.

Summer Time All Year Round?

Over the past few decades, there have been frequent unsuccessful attempts in the UK parliament to make changes to the current system. Campaigners for the return to “British Double Standard Time,” or a permanent British Summer Time, argue that an extra hour of light in the afternoon could mean fewer road accidents, more leisure time, and a boost to tourism and energy efficiency.

  • In 2010, the UK government discussed “Single / Double Summer Time,” where the local time is 1 hour ahead of GMT during the winter and 2 hours in the summer.
  • The Daylight Saving Bill 2010-12 proposed to put the UK on permanent BST, but it was not passed in the House of Commons.

Time in the UK Today

Today the United Kingdom observes Greenwich Mean Time (GMT) during the winter months and British Summer Time (BST) in the summer months.

The country follows the same DST schedule as most of Europe, setting the clocks forward 1 hour on the last Sunday in March and back again 1 hour on the last Sunday in October.

Topics: Time Zone