Coinciding with Mother’s Day and bringing an hour’s less sleep for hard-pressed parents, British Summer Time has arrived but it may seem less welcome than normal this Sunday.

The subject of daylight saving, with a view to giving us lighter evenings, has long been one of controversy and debate.

Clocks have gone forward one hour on March 31 this year.

Here we look at why we move the clocks forwards and backwards at the beginning and end of summer.

When was British Summer Time introduced?

Horologist James Harris dusts a French-made mechanical clock at The Clockworks Museum in London, where they have the task of putting their collection of clocks forward an hour. Credit: Kirsty O’Connor/PA

It started in 1916, during the depths of the First World War, a month after Germany brought in daylight saving measures to reduce its industrial demand for coal.

After the war, the move became permanent and since then the UK has changed its clocks to reflect the desire to have lighter evenings in the summer months for citizens to enjoy their leisure.

But, we've tried year-round BTS before.

In 1968-1971, the British Standard Time experiment was introduced by the government of then Prime Minister Harold Wilson, with Britain remaining on GMT +1 throughout the year. The result was a large reduction in road casualties thanks to the lighter evenings, but the experiment was ended due to complaints from northern parts of the UK, where mornings were darker as a result.

More time during the lighter, summer evenings allows people to be more active. Credit: PA Graphics

What are the arguments for Daylight Saving Time (DST) around the world?

More time during the lighter, summer evenings allows people to play sports, get outside and enjoy the better weather after the typical working or school day is done.

Health experts suggest it is a strong weapon against childhood obesity as DST encourages youngsters to get outside in the fresh air and remain active into the evening.

More exposure to sunlight is also good for the mood of the nation as it helps fight depression.

Proponents argue Daylight Saving Time encourages people to be more active. Credit: Kirsty O’Connor/PA

Supporters of DST also say it saves energy consumption by reducing the need for lighting and heating into the evenings, although this is disputed.

The Royal Society for the Prevention of Accidents (ROSPA) says the number of vulnerable people killed in road accidents spikes after the clocks go back in autumn.

The most recent research estimates that adopting British Summer Time would have the net effect of saving around 80 lives and 212 serious injuries a year, although this estimate is now quite old.

It argues we should stick with BST all year round.

The evening commute will be darker if the clocks permanently go back one hour. Credit: PA

Why do some people argue against it?

Losing an hour’s sleep when the clocks go forward can cause health risks, studies have shown.

The number of heart attacks increases in the fortnight after the change, with a peak on the Monday morning immediately following the switch.

People can feel disorientated for some time after the hour change and it is argued this can lead to accidents in the home.

A good night's sleep is exactly what the doctor ordered

The Sleep Disorders Clinic in London carried out research into the effects the sudden change in sleep can have on your body. They concluded there can be cause for concern for a minority of people with underlying health conditions.

Joseph Gannon, 29, Chief Sleep Physiologist and Clinical Lead said: ‘If you’re healthy, have a good amount of sleep and are young, there’s not too much of a consequence.

‘The people it can affect are those that are already sleep deprived, particularly with conditions such as sleep apnea.'


Serious injuries saved if we stuck to BST year-round

More studies across the world have found an annual spike in heart attacks in Michigan in the US and strokes in Finland the day after the clocks go forward in March.

Many of these deaths are likely to have been in elderly people but some could be due to loss of sleep: there’s evidence that heart attacks are most common on Mondays, possibly due to sleep lost while readjusting to the schedule of the working week.


Lives could be saved if we stuck to BST year-round

Many farmers, particularly in northern England and Scotland, are opposed to keeping BST through the year as they prefer to have lighter mornings to carry out their work.

If it was brought in permanently, children in higher latitudes would be going to school in the dark.

Some argue changing clocks twice a year is an unnecessary hassle.

What has the European Union proposed?

MEPs have voted to scrap the twice-yearly clock changes.

Should governments agree, EU states will decide whether to stay on permanent “winter time” or “summer time” from 2021.

This would apply to the UK during any Brexit transition period, as ITV News previously reported:

What happened when Parliament debated changing the system?

A Private Member’s Bill to put the clocks forward an hour was talked out by opponents in 2012 and did not come into law.

Jacob Rees-Mogg, Tory MP for North East Somerset, proposed giving Somerset its own timezone, 15 minutes behind the rest of the country.

It was his way of highlighting deficiencies he saw in the proposed bill.