Uses of Time

» On Sunday, October 26, we will once again set back our clocks by one hour to enter winter time. This change – which affects millions of people in Europe every year – is accompanied by new scientific evidence that confirms its negative impacts on health and reopens the debate on its definitive elimination.

A study by Stanford University warns of health risks

On September 15, the scientific journal PNAS published a study by Stanford University that concludes that changing the time twice a year is harmful to public health. According to researchers Lara Week and Jamie M. Zeitzer, reversing this practice could prevent thousands of strokes and reduce obesity rates in the United States.

The study uses a mathematical model that compares the impact of three time policies – standard time, daylight saving time and the biannual change – on circadian rhythms, the internal clock that regulates sleep, appetite and other vital functions. When natural light does not coincide with daily activity, the biological clock becomes desynchronized, which can lead to sleep disorders, increased stress and cardiovascular risks.

The conclusions indicate that maintaining a fixed schedule is healthier than making two annual changes, and that standard time is the best option, as it prioritizes morning light and reduces the “circadian load”, that is, the body’s effort to synchronize with sunlight.

According to the authors’ calculations, keeping standard time permanently could prevent 300,000 strokes and reduce the number of people with obesity in the United States by 2.6 million each year. Permanent daylight saving time would also offer benefits, albeit more modest.

Europe reopens the debate on the elimination of time change

2026 could be the year in which Europe puts an end to the biannual time change. Last October 20, the Spanish government announced its support for this elimination and committed to defending the proposal before the Council of the European Union, the body in charge of its final approval.

The European Commissioner for Energy, Dan Jorgensen, highlighted the importance of finding a common position among member states and responding to a demand that has the support of 80% of European citizens.

After being stopped in 2020 due to the pandemic, the debate has resumed in 2025 with the support of representatives of the European Parliament and experts who propose to abolish seasonal changes and adopt a permanent timetable, as close as possible to solar time in each country.

The Barcelona Declaration advocates for a Europe without time change

The Barcelona Declaration on Time Policies, promoted by Barcelona City Council and signed by more than 200 institutions and organisations from around the world, advocates for the elimination of time change as a key measure to move towards a healthier, more sustainable and equitable time organisation.

This international commitment, aligned with the latest scientific research, aims to put an end to the seasonal time change in Europe by 2026, contributing to the well-being and health of citizens.