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In his 2017 bestseller Why We Sleep, the scientist Matthew Walker describes a horrifying sounding global experiment in which 1.5 billion people are forced to reduce their sleep by one hour or less for a single night each year. If you live in Europe or North America, he says, it’s very likely you have been part of this experiment: it’s known as daylight saving time, or DST for short. And, once again, it’s back. But not for long.

DST, it turns out, is a terrible idea. On the days after people lose an hour of sleep (this weekend the UK springs forward into British Summer Time, in October we fall back into Greenwich Mean Time), researchers tabulating millions of hospital records found a significant spike in heart attacks and car accidents in the Northern Hemisphere. A 2016 study also found that in Finland strokes go up by eight per cent in the two days after DST.


Stats like this are one of the reasons the European Parliament approved a measure this week, by a landslide of 410 to 192, to abolish the twice-yearly clock change. The change has been delayed until 2021 – but the end of DST in Europe is now inevitable. The European Commission says it will be up to individual member states to decide whether they live permanently on winter or summer time, but once the final switch happens it will be permanent. And, according to experts, it’s about time.

“[Traffic accidents] prove that the brain, by way of attention lapses and microsleeps, is just as sensitive as the heart to the very small perturbations of sleep,” says Walker. “Most people think nothing of losing an hour of sleep for a single night, believing it to be trivial and inconsequential. It is anything but.”

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So where did DST come from? The practice originated in Germany, during the First World War – April 30, 1916, to be precise – in order to conserve energy by making the most of the available daylight hours. Most European nations would slowly adopt similar seasonal changes, if intermittently: the UK and Ireland abandoned the practice in 1968 only return to it 1972. Finally, in 1996, the EU unified the continent under one system, European summer time, observed from the last Sunday in March to the last Sunday in October.

So why is the EU scrapping it? Well, firstly, because the move is extremely popular. A public consultation carried out in August 2018 drew over 4.6 million votes, the most ever received by the EU. It found that 84 per cent of respondents across 28 member states were in favour of putting an end to the bi-annual clock change.


Secondly, there is a large body of evidence that shows DST is harmful to both public health and the economy. “My own research shows spikes in work injuries and cyberloafing, and dips in moral awareness are all associated with the dip in sleep,” says Christopher Barnes, associate professor of management at the Foster School of Business in Seattle, Washington, who has done multiple studies on the effects of the clocks going forward and back. Cyberloafing is defined as spending work hours checking personal emails or visiting websites not related to work – basically, your brain, confused by the small but sudden change, has checked out.

Using a National Institute for Occupational Safety and Health database of mining injuries in the US between the years 1983 and 2006, Barnes also determined that on the Mondays after the clocks go forward employees slept 40 minutes less, had 5.7 per cent more workplace injuries and lost 67.6 per cent more work days because of injuries.

Even the historical reason given for DST, saving energy costs, is based on wobbly reasoning. “Research examining the effect of the DST policy on energy costs is a mixture of papers showing no effect and other papers showing that the DST policy actually results in greater energy consumption,” Barnes adds. “So the benefit to DST is minimal to nonexistent, and the costs and harms associated with it are real and meaningful.”

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There’s also an economic angle to the EU’s move. One study by the Rand Corporation, an American non-profit, found that inadequate sleep cost the UK economy £50 billion a year – equivalent to 1.9 per cent of GDP – due to decreased productivity and sickness.


So how is this decision affected by Brexit? If and when the UK does leave the EU, it would be free to keep using DST. But such a move would be a disaster, especially on the island of Ireland, where Northern Ireland and the Republic of Ireland could end up an hour apart. Economically and socially, all the evidence suggests that the EU needs to move as one when it comes to DST.

And the change that’s started in the EU could soon spread overseas. “I’m glad to hear that the EU is moving in that direction,” says Barnes. “My own home state of Washington has some early stage legislation under consideration to do the same, and I hope it passes.”

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