At three o’clock in the morning on the night of Saturday to Sunday, it will be two o’clock. It will therefore be necessary to think about setting back clocks and other alarm clocks by 60 minutes, which will allow everyone to enjoy an extra hour of sleep.

Afterwards, bonus for early risers: they will benefit from a little more light in the early morning with, in return, a night which will fall earlier at the end of the day.

This change, introduced for the first time in 1916 before being abandoned in 1944, was reintroduced by a decree in September 1975. It was intended to be temporary and aimed to limit energy consumption in the midst of the oil crisis.

With the return of the issue of energy resources in a burning way due to the war in Ukraine and the multiplication of calls for energy sobriety, the transition to winter time could appear beneficial. But is it really?

– Minimal effect –

In fact, the time change has only a minimal effect on energy consumption.

Thus, in 2009, according to the Ecological Transition Agency (Ademe), the switch from winter time to summer time led to lighting gains of around 440 GWh, i.e. 0.07% of total electricity consumption. Lighting using partly carbon-based means of electricity production, these savings represented a gain of around 50,000 tonnes of CO2.

But since then, this effect has tended to diminish due to the increased performance of lighting systems (low-consumption bulbs and LEDs). In 2018, this drop was only 351 GWh. By 2030, energy savings in lighting are estimated at 258 GWh by Ademe.

Knowing that in addition the majority of household energy consumption comes from heating and not from lighting, the evidence of energy savings therefore remains to be demonstrated.

Worse, a recent British study claims that scrapping the clock change in October would save £400 (460 euros) per household per year, as it would be light longer in the evening, reducing demand during point.

The transition to winter time is also criticized for its effects on biological rhythms, in particular by doctors or parents of school-age children who report consequences on sleep, mood or sleep disorders. ‘Warning.

– Hourly patchwork –

At European level, where the time change regime was gradually generalized in the 1980s before being harmonized in 2002, the European Commission had proposed in 2018 to abolish it… in 2019. But the European Parliament voted in March 2019 a postponement to 2021 and had to agree with the Council of Heads of State and Government on the modalities.

Since then, between Brexit and the global Covid pandemic, the question has remained unresolved. One of the difficulties is to encourage countries to harmonize their legal time (summer or winter) in order to avoid ending up with a patchwork of time zones.

In France, an online consultation organized in early 2019 by the National Assembly had received more than two million responses, overwhelmingly (83.74%) in favor of the end of the time change. More than 60% of participants claimed to have had «a negative or very negative experience» of the change. As for the time to stay all year round, summer time (in France GMT 2) was preferred by 59% of them.

Particularity of the current system: it does not concern overseas territories which never change time (with the exception of Saint-Pierre-et-Miquelon which is based on neighboring Canada). Indeed, most of them are in latitudes where the variations in sunshine are low throughout the year, unlike Europe.

Worldwide, several countries, such as Argentina, Tunisia, Egypt, Turkey, Russia or Armenia have already decided to abandon seasonal time changes.