When do the clocks change, why do we use British Summer Time –and do we still need to?

Cameron Macphail
Antique clock seller Howard Walwyn goes through his shop in Kensington, London, changing the time on all the clocks - John Nguyen/JNVisuals

The nights are becoming lighter and although the recent snowfall may suggest otherwise, the temperature is very slowly starting to get warmer – which can only mean the clocks will change soon.

But when and why do lose an hour each spring – and should we get rid of the practice altogether? Here is everything you need to know about springing forward.

When do  the clocks go forward?

On Sunday, March 25 we will move to British Summer Time (BST) – at 1am, to be precise. The clocks will move forward (remember the Americanised mantra: spring forward, fall back).

When do the clocks go forward? | Sunday 25th March 2018 at 1 am

What is Daylight Saving Time?

Daylight saving time (DST), or summer time, is the practice of advancing clocks during summer months by one hour so that in the evening daylight is experienced an hour longer, and normal sunrise times are sacrificed.

Typically, regions with summer time adjust clocks forward one hour close to the start of spring and adjust them backward in the autumn to standard time.

In the UK, the maximum 16 hours and 50 minutes of sunlight occurs on the longest day in June (the summer solstice) and dwindles to just seven hours and 40 minutes six months later in December (the winter solstice).

Studies have shown it leads to a general sense of wellbeing, cognition and fewer accidents on the roads.

Whose idea was it – and why do the clocks change?

During the nine years he spent as American ambassador to France, American inventor and politician Benjamin Franklin wrote an essay titled An Economical Project for Diminishing the Cost of Light to the editor of The Journal of Paris in 1784.

In the essay, he suggested that Parisians could reduce candle usage by getting people out of bed earlier in the morning, making use of the natural morning light instead.

More than one hundred years later, in 1895, an entomologist in New Zealand, George Vernon Hudson, outlined a daylight saving scheme to the Wellington Philosophical Society, which was trialled successfully in the country in 1927.

William Willett was the man who introduced the idea of Daylight Saving Time in Britain in 1907. He was keen to prevent people from wasting vital hours of light during summer mornings.

Willett (who, incidentally, is the great-great-grandfather of Coldplay lead singer and 'Clocks'-writer Chris Martin), published a pamphlet called 'The Waste of Daylight' in a bid to get people out of bed earlier by changing the nation’s clocks.

Willett proposed moving the clocks backwards and forwards by 80 mins, setting the clocks ahead 20 minutes on each of the four Sundays in April, and switching them back by the same amount on each of the four Sundays in September, a total of eight time switches per year. 

William Willett laid out a serious proposition for the daylight saving scheme Credit: Getty Images

Supporters for the proposal argued that such a scheme could reduce domestic coal consumption and increase the supplies available for manufacturing and the war effort during the First World War.

Willett spent the rest of his life trying to convince people his scheme was a good one. Sadly, he died a year before Germany adopted his clock-changing plan on April 30, 1916, when the clocks were set forward at 11pm. Britain followed suit a month later on May 21.

By then Britain and Germany had been fighting each other in the First World War (1914-18), and a system that could take pressure off the economy was worth trying.

The Summer Time Act of 1916 was quickly passed by Parliament and the first day of British Summer Time, 21 May 1916, was widely reported in the press.

Back then the hands on many of the clocks could not be turned back without breaking the mechanism. Instead, owners had to put the clock forward by 11 hours when Summer Time came to an end.

The Home Office put out special posters telling people how to reset their clocks to GMT, and national newspapers also gave advice.

Even though Germany is commonly known as the first country to implement DST, Thunder Bay in Ontario, Canada had implemented DST in 1908.

Willett is commemorated for his efforts by a memorial sundial in nearby Petts Wood, set permanently to Daylight Saving Time. The Daylight Inn in Petts Wood is named in his honour and there's a road there called Willett Way.

Which countries use Daylight Saving Time?

EU countries which synchronise their DST include the UK, France, Germany, Spain, Italy and Bulgaria as well as most other European countries – including Norway and Switzerland. A few European countries don't use DST at all: Russia, Iceland, Georgia, Armenia and Belarus.

Most of the United States begins Daylight Saving Time at 2am on March 11.

Daylight Saving Time occurs in US states and territories except Arizona, Hawaii, Puerto Rico, the Virgin islands, American Samoa, Guam, and the Northern Mariana Island. Utah is considering the ending its participation in DST.

From 1986-2006, Daylight Saving Time in America began on the first Sunday in April and ended on the last Sunday in October. The current timetable for Daylight Saving Time was introduced on Aug 8th 2005, however, when President Bush signed the Energy Policy Act.

Many countries in the Northern Hemisphere (north of the equator) observe DST, but not all. In the Southern Hemisphere the participating countries start DST between September and November and end between March and April.

Has the time difference always been one hour?

Today clocks are almost always set one hour back or ahead, but throughout history there have been several variations, like half adjustment (30 minutes) or double adjustment (two hours), and adjustments of 20 and 40 minutes have also been used. A two-hour adjustment was used in several countries during the 1940s and elsewhere at times.

A half adjustment was sometimes used in New Zealand in the first half of the 20th century.

Australia's Lord Howe Island (UTC+10:30) follows a DST schedule in which clocks are moved 30 minutes forward to UTC+11, which is Australian Eastern Daylight Time (AEDT) during DST.

Lord Howe Island with Ned's Beach in foreground and Mount Lidgbird and Mount Gower behind Credit: AFP

In 1940 during the Second World War, the clocks in Britain were not put back by an hour at the end of Summer Time. In subsequent years, clocks continued to be advanced by one hour each spring and put back by an hour each autumn until July 1945.

During these summers, therefore, Britain was two hours ahead of GMT and operating on British Double Summer Time (BDST).

The clocks were brought back in line with GMT at the end of summer in 1945. In 1947, due to severe fuel shortages, clocks were advanced by one hour on two occasions during the spring, and put back by one hour on two occasions during the autumn, meaning that Britain was back on BDST during that summer.

Why we should get rid of Daylight Saving Time

Those against DST say its not clear if any energy savings are made while there are also potential health risks.

Critics claim that the darker mornings are dangerous for children walking to school and the energy saving argument may be invalid if people switch on fans and air-conditioning units during the lighter, warmer evenings. (But this is unlikely to bother people in the UK.)

In 2011, Tory MP Rebecca Harris floated a bill calling for year-round daylight savings but it failed to complete its passage through Parliament before the end of the session and was dropped.

A YouGov poll that same year found that 53pc of Britons supported moving clocks forward an hour permanently while 32pc opposed the change.

The proposals were met less warmly by the Scottish population; Alex Salmond called the campaign an attempt to “plunge Scotland into morning darkness" and his SNP colleague MP Angus MacNeil said any change would have "massive implications for the safety and wellbeing of everyone living north of Manchester".

Horologist Roman Piekarski in the time-consuming act of adjusting the antique clocks at Cuckooland Museum in Tabley Credit: Lynne Cameron/PA Wire

"It is no secret that Tories in the south want to leave Scotland in darkness, but fixing the clocks to British summertime would mean that dawn wouldn't break in Scotland until nearly 9am," he said.

He had a point. Following a 1968 to 1971 trial, when BST was employed all year round northern Scotland saw a net increase in the number of people killed or seriously injured.

The sun wouldn’t rise until 10am in parts of Scotland and the country’s 1,000-or-so dairy farmers, who wake up before 5am, would have to work for hours in the dark.

Other farmers and construction workers, who need sunlight to perform their jobs, would end up having to work later into the evening.

Some folks keen to reach a compromise have suggested the clocks change at Hadrian's Wall and not at Calais.

Philip Broom writing on the National Farmer's Union website in 2011 said: "A definite no. Combining will not start until midday and then have to go on until 11 o’clock. Our day is long enough now."

An A Thomas, also writing on the NFU site, was worried that "younger people having loud parties or barbecues in gardens and youths hanging around on streets would make it a nightmare for people getting up for work early mornings."

Clocks in popular culture

Why we should keep Daylight Saving Time

The current system of changing the clocks at the end of March and October has been in place since 1972.

Those in favour of not changing the clocks back in October say that it would reduce traffic accidents, save energy, boost tourism and encourage more people to exercise outdoors.

In the 1980s, the golf industry estimated that one extra month of daylight savings could generate up to $400 million (£246.6 million) a year in extra sales and fees.

Daylight Savings Time “affects everything from Middle-East terrorism to the attendance at London music halls, voter turnout to street crime, gardening to the profits of radio stations,” said David Prerau, author of Saving the Daylight: Why We Put the Clocks Forward.

This debate stretches years into the past, and the future of British time is still unclear.

A right royal wind-up

One down, 900 odd to go: A member of the Queen's staff at Windsor Castle adjusts a clock from the Royal Collection Credit: Royal Collection Trust / © Her Majesty Queen Elizabeth II 2015

Spare a thought for the staff of the Royal Collection. They spend over 50 hours adjusting over 1,000 clocks spread across the official residences of The Queen.

Following months of planning, staff at Buckingham Palace, Windsor Castle and the Palace of Holyrood house in Edinburgh start work in the early hours of the morning to ensure that the time is set accurately.

There are 379 timepieces at Windsor Castle, 500 at Buckingham Palace and 80 at the Palace of Holyroodhouse including organ clocks, astronomical clocks, musical clocks and mechanical clocks.

What was Sandringham Time (GMT+30mins)?

An added complication for Royal servants between the years 1901 to 1936 was the concept of 'Sandringham Time' which was introduced in by Albert, Prince of Wales, later King Edward VII.

A keen fan of shooting, he wanted to make the most of winter daylight, so he ordered all clocks on the estate to be set half an hour fast.

The tradition was continued by King George V after he acceded to the throne in 1925 but King Edward VIII abolished it in 1936 shortly before his abdication.