Turning back the clocks is a waste of time

Last Sunday, at the annual meeting of the Society for Neuroscience in San Diego California − the biggest event in the field, attracting about 30,000 participants – a timely symposium took place. Researchers from the University of Washington and the Salk Institute shared results from a study conducted in Seattle high schools that opted to start their classes at 8.45am, instead of the usual 7.50am. This additional 55-minute lie-in led to healthier sleeping habits, better academic performance and higher school attendance.

Like everyone else in the US, those who attended had also benefited from one additional hour of sleep. The clocks had moved back one hour the night before, marking the end of daylight saving time.

The practice of changing the clocks has been gradually implemented around the world over the past century, and is now in effect in 70 countries. It is said that adopting the system allows nations to make the most of changing patterns of natural daylight, saving both energy and money.

On paper, this sounds like a great idea. But over the years, unintended economic and health consequences have emerged.

It turns out that these minor changes to mechanical clocks can lead to significant disruption of internal, biological ones.

One of the most important changes is in the neurobiological regulation of melatonin in our bodies. Melatonin is a hormone that plays a key role in modulating sleeping patterns.

It is naturally produced and released when darkness is detected by our brains, and stops being produced when it detects light. Melatonin tablets are often used by people travelling across timezones to catch up with sleep and fight jetlag.

When the clocks go back, daylight hours become shorter and the body produces melatonin earlier in the day. The results of this reach far beyond people yawning over dinner and falling asleep on the couch in front of the television. Changing the clocks affects our daily lives more than we might at first imagine.

Peer-reviewed research has shown significant increases in car accidents, crime, workplace injuries, workdays lost and adverse stock market performance when the clocks go either forward or back. A 2016 study published in

Psychological Science even reports judges giving longer sentences in US federal courts immediately after the introduction of daylight saving time.

The impact upon people’s physical health has been revealed in an analysis of six studies, including a total of 87,994 cases of acute myocardial infarction (AMI), or heart attack, published in February in the European Review for Medical and Pharmacological

Sciences. The authors state that: “All studies confirmed a higher occurrence of AMI in the spring [daylight savings] shift, ranging from 4 per cent to 29 per cent, whereas only one study showed a higher occurrence of AMI in the autumn shift”.

There is also a growing consensus that, far from being a sound economic measure, applying daylight saving time costs countries hundreds of millions of dollars each year in lost productivity. Changing the clocks appears to provide yet another example of policy being adopted before its impact on people’s lives has been properly assessed.

Now, the entire concept is being challenged by around the world, starting with the member states of the European Union.

The opportunity cost of the EU’s mandatory clock-changing policy and a possible revision of the 2001 directive that governs it is being assessed. Between July and August, the European Commission ran an online public consultation across its 28 members to gauge public opinion on changing their respective clocks twice a year.

A total of 84 per cent of the 4.6 million respondents − a record for a European Commission consultation, but a sample group that still only represents 1 per cent of the total EU population − expressed their willingness to put an end to it altogether, with more than three-quarters of them considering it a “negative” or “very negative” experience. Should their voices be heard, daylight saving time could become a thing of the past in the EU, as member states are freed to choose their own summertime arrangements.

However, even if the global trend seems to lean towards dropping daylight saving, Japan, which abandoned the biannual change in 1951, is considering moving the clocks forward two hours for the 2020 Summer Olympics in Tokyo – a measure similar to the one taken by South Korea in 1988 for the Seoul Olympics. The goal is to protect the health of athletes by allowing them to compete at times when the temperature is lower. Unsurprisingly, Japanese economists are squabbling over the projected consequences of this plan.

One thing is for sure, when it comes to the debate on daylight saving, we will need a little more time to settle it.

Instead of making sound economic sense and conserving energy, daylight saving plays havoc with our bodies