Last week, Europe joined the United States in shifting the clocks forward an hour. Who doesn’t look forward to ‘summer time’, with its promise of long, warm evenings for strolling, al fresco dining and working the fields? Circadian biologists don’t; many of them greet the new time with a seasonal chorus of ‘Foul!’

For many, the time shift known as daylight saving is a burdensome disruption. Some people do not adjust well at all, as witnessed by reports of increased incidence of heart attacks and traffic accidents the day after the change. Our ‘chronotype’ — whether we are early-to-rise larks or committed night owls — is set in our genes, and chained to the light–dark cycle of the Sun. It is not going to be that easily deceived by the hands of our watches and clocks, which now only loosely attach to true astronomical time, and to true biological time.

In fact, the very notion of an agreed time at which we should all wake and pay attention — to bosses, teachers and traffic — is misplaced. A huge research effort at the Ludwig Maximilian University of Munich known as the human sleep project has shown the hopelessness of trying to alter preferred wakefulness patterns.

The project began in 2000 with the launch of a web-based questionnaire about sleep and wake times on working days and free days. A quarter of a million individuals around the globe have since participated. It provides a rich source of research data, and one mined with particular glee by those chronobiologists who are natural owls and have a grudge against a society that habitually imposes inflexible school and work times.

A landmark study of the data showed that late and early chronotypes have a bell-curve distribution across all populations. And within their own chronotype, all individuals are, relatively speaking, earlier risers as children, become much later as adolescents and then become slowly earlier as adults (T. Roenneberg et al. Curr. Biol. 14, R1038–R1039; 2004).

Another study, which considered data from across Germany, demonstrates the unrelenting power of the Sun (T. Roenneberg et al. Curr. Biol. 17, R44–R45; 2007). The country spans nine degrees of longitude, so the Sun rises 36 minutes earlier at its most easterly point compared with its most westerly. Whatever their individual chronotype, physical and biological time for these people diverges on average by an extra four minutes with each longitudinal step.

We need flexibility not in the time displayed by the clock, but in our attitude to it.

The discomfort that some of these chrono-victims feel is magnified across the vast geographical swathe of Central European Time. In summer, midnight on the clock is, astronomically speaking, actually 11 p.m. in the Czech capital, Prague, but barely 9.30 p.m. in the western Spanish outpost of Santiago de Compostela. The Spanish habit of dining at 10 p.m., when many Czech restaurants have long since closed, starts to make sense.

Other studies have shown the power of biological time. Night owls, including adolescents who are driven sulking from their beds to attend school long before they are truly awake, spend large parts of their weekends ‘catching up’ on missed sleep (M. Wittmann et al. Chronobiol. Int. 23, 497–509; 2006).

And placing activity meters on wrists to monitor movements 24–7 shows that, although people will adjust their bedtimes to daylight-saving time, peaks and slumps in their activity remain ruled by their separate, fixed, biological clocks (T. Kantermann et al. Curr. Biol. 17, 1996–2000; 2007).

Whereas the power of astronomical and biological time remains, modern life weakens the light–dark cycle that connects them. City dwellers tend to spend most of their days working indoors, where lighting levels can be 40 times weaker than average daylight. Night time is no longer particularly dark thanks to electric lighting both indoors and in the streets. Camping experiments in the mountains, in which people have to live outside during daylight hours and have no source of light beyond the campfire, show that night owls quickly become much earlier chronotypes.

Daylight-saving time is far from universal. And experience in other countries shows that it is not necessary. Japan and South Korea, like most Asian countries, see no need for it. Most African countries don’t either. Ukraine observes it — but after annexation by Russia in 2014, Crimea chose to align its time with Moscow, which does not observe daylight saving.

In Europe, some politicians, prodded by data on the counter-productivity of enforcing inflexible social timetables across an entire population, and also by evidence that shift workers who live against their biological clocks have a higher incidence of metabolic diseases, have opened a debate on the value of making the change every six months.

Fixing time will not fix its problems. To do that, we need flexibility not in the time displayed by the clock, but in our attitude to it. One high school in Germany this year decided to allow its older students the option of beginning classes at 8.50 a.m. instead of 8 a.m., anticipating that the adolescents would be more alert and capable of learning by then. Britain is looking at changes too. Perhaps more of society should wake up to the opportunities.