Time change: origin, impacts and future of this practice

Every year, the French move their watches forward or backward twice, in the spring and fall. This ritual, established to better align activity schedules with daylight, is the subject of recurring debates on its real usefulness. Some see it as an obsolete measure, while others believe that it remains relevant to limit energy consumption.

Why does this practice still exist today? Does it have a real impact on our daily lives? And above all, will it disappear in the years to come?

The origins of time change: a centuries-old idea

The idea of ​​changing the time to take better advantage of daylight is not new. In 1784, Benjamin Franklin, then ambassador of the United States to France, observed that Parisians were still sleeping even though the sun had already risen. He then came up with a system to encourage the population to wake up earlier and save on candles.

This principle remained theoretical for a long time until it was applied for the first time in 1916, during the First World War. Germany, seeking energy savings to support the war effort, introduced summer time. Very quickly, France, the United Kingdom and the United States adopted this measure to reduce their consumption of coal and electricity.

At the end of the conflict, this practice was abandoned but reintroduced by some countries during the Second World War. In 1941, France, then under German occupation, adopted Berlin time (GMT+2) to standardize time zones between the controlled territories. After the Liberation, France briefly returned to GMT+1 but without definitively settling on a clear system.

Why did France reintroduce the time change in 1976?

The decision to reinstate the time change in France came after the first oil crisis in 1973. Faced with soaring energy prices, the government of Valéry Giscard d'Estaing sought solutions to reduce electricity consumption. In 1976, the summer time system was officially reintroduced with a clear objective: to better match work and activity schedules with sunshine to limit the use of artificial lighting.

The argument put forward is based on a simple observation: by moving the clocks forward in the summer, the French benefit from an extra hour of natural light at the end of the day, thus reducing their need for electricity. At the time, this change was seen as an effective measure to achieve energy savings on a national scale.

How does the time change work today?

Since 1998, the dates for switching to summer and winter time have been harmonised within the European Union. From now on, all member countries apply the same rules:

The switch to summer time takes place on the last Sunday in March.
The change to winter time takes place on the last Sunday in October.

In the rest of the world, the situation is more contrasted. Some countries, such as Russia, China or Japan, have abandoned the time change, judging its harmful effects on health and productivity. Others, such as the United States and Canada, continue to apply it but with specific calendars.

Is the time change still relevant today?

While the initial goal was to reduce energy consumption, the real benefits of changing the time are increasingly being contested. With changing lifestyles and the rise of energy-saving light bulbs, the savings made through this measure have become marginal. According to some studies, the energy gain would not exceed 0.5% of annual electricity consumption.

At the same time, many studies have highlighted negative effects on health. The time change disrupts the biological rhythm, causing sleep disorders, increased fatigue and a drop in concentration, especially in the days following the change to summer time. Some experts go so far as to associate it with an increase in the number of road accidents and cardiovascular disorders.

From an economic and social point of view, the impact of the time change is also subject to debate. While it can promote certain outdoor activities thanks to longer days, it complicates the management of schedules in transport, commerce and international trade.

Towards the abolition of time change in Europe?

In the face of these criticisms, the question of abolishing the time change has been raised several times within the European Union. In 2018, a public consultation conducted by the European Commission revealed that 84% of European citizens were in favour of abolishing this measure.

Following these results, Europe decided to act on the end of the time change, while leaving each country the choice of whether to stay permanently in summer time or winter time. But since then, the issue has been at a standstill. Member States are struggling to find a consensus, each having different preferences depending on their latitude and time zone.

In France, the debate remains open. Some argue for maintaining summer time in order to maximize light in the evening, while others prefer winter time, considered closer to the natural rhythm of the sun.

The time change, introduced for energy and economic reasons, is now being questioned. While its impact on electricity savings is increasingly contested, its negative effects on the health and daily lives of citizens are fueling the debate on its relevance.

While the European Union has begun to consider putting an end to this practice, the lack of agreement between the States is holding back any concrete developments. It remains to be seen whether this measure, which has been a part of our lives for decades, will eventually disappear or whether it will remain anchored in our habits.