The time is...British Summer Time explained

Why you are losing an hour of sleep this weekend

The clocks go forward an hour at 1am on Sunday 30 March (AFP/Getty)

Spring forward; fall back. In the early hours of Sunday morning, the country will lose an hour’s sleep as the clocks go forward to mark the start of British Summer Time (BST).

At 1am on 30 March, civil time in the UK will be fast-forwarded one hour ahead of Greenwich Mean Time (GMT), heralding longer, lighter evenings and, hopefully, the tentative beginnings of summer.

In today’s digitalised world many people don’t have to worry about adjusting the hands on a clock - but here’s the reasoning behind it.

What is British Summer Time?

The idea of British Summer Time was first proposed in the UK by William Willett, who happens to be the great-great-grandfather of Coldplay frontman Chris Martin. He felt that valuable daylight was being wasted in the mornings during the summer months because people were still in bed.

In 1907 he published a pamphlet called The Waste of Daylight, in which he outlined his plans to change the time of the nation’s clocks. But when he died in 1915 the Government still refused to back BST.

It wasn’t until a year later, in May 1916, that Britain passed the Summer Time Act and started changing its clocks twice a year.

What are the benefits?

Proponents argue that British Summer Time is good for physical and psychological health, particularly in terms of relieving the symptoms of Seasonal Affective Disorder (SAD).

The lighter evenings are also said to reduce road traffic accidents and crime.

And the downsides?

Well, there’s always the risk of turning up late for a family dinner/ football match/ church service. But, on a more serious note, critics have said that changing the clocks is economically and socially disruptive, therefore cancelling out any benefits.

There are also a number of theories that suggest putting the clocks forward has a negative impact on the human body – in 2012 a University of Alabama study found the risk of a heart attack surges by 10 per cent on the Monday and Tuesday after moving the clocks forward.

What is British Double Summer Time (BDST)?

In 1940, during the Second World War, clocks across Britain were not put back an hour at the end of British Summer Time, in order to save fuel and money.

However, in subsequent years, they continued to be put forward an hour each spring and then put back an hour each autumn until July 1945. This meant that during these summers the UK was two hours ahead of GMT .

So when exactly do the clocks go forward?

British Summer Time begins on Sunday 30 March. This means you should put your clocks forward at 1am on Sunday 30 or, failing that, before you bed down for the night on Saturday.