While the summer plays extra time, France will however have to put itself, Sunday, October 30, at winter time; a controversial change whose abolition, decided three years ago by the European Union, looks like a sea serpent. At 3 o’clock in the morning, on the night of Saturday to Sunday, it will be 2 o’clock. It will therefore be necessary to think of setting back clocks and other alarm clocks by sixty minutes, which will allow everyone to benefit from an additional hour of sleep.
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? What are the flaws of this device?
1. A non-universal and difficult to understand system
At European level, where the time change system was gradually generalized in the 1980s before being harmonized in 2002, the European Commission had proposed in 2018 to abolish it… in 2019. But, in March 2019, the Parliament European voted 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 Covid-19 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 at the beginning of 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” change.
Special feature 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 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 and Armenia, have decided to abandon seasonal time changes.
2. Inconclusive energy gains
The main argument in favor of the time change has so far been the energy savings it would achieve by taking advantage of longer daylight periods in summer and getting closer to the rhythm of the sun in winter. But several studies on the subject show savings in energy and CO2 “modest”according to the French Environment and Energy Management Agency (Ademe).
Thus, a study by Ademe published in 2010 shows that the switch to summer time leads to:
- higher electricity consumption in the morning, notably with a peak at 6 a.m. (equivalent to 5 a.m. in winter time);
- much lower consumption in the evening, especially between 8 p.m. and 9 p.m. (equivalent to the period between 7 p.m. and 8 p.m. in winter).
In other words, households pay, on average, a little more in electricity in the morning but ultimately save in the evening. To get an idea, one hour less lighting saves about 0.10 euro.
In 2009 (the year taken into account by the study), the average demand for electricity at 7 p.m. was thus reduced by 3.5 gigawatts (GW). In total, the energy saving that year was calculated at 440 gigawatt hours (GWh), mainly on public lighting (in pink in the graph above), the equivalent of one year of lighting for a city of 800,000 inhabitants, like Marseille.
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 gigawatt hours. By 2030, energy savings in lighting are estimated at 258 gigawatt hours by Ademe.
Knowing that 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 removing the clock change in October would save £400 (460 euros) per household per year, as it would be light longer in the evening, which would reduce demand during point.
3. Conflicting results on road accidents
The Association against double summer time is campaigning against the time change citing, among other reasons, “increases in traffic accidents”. She bases her argument on figures dating from… 1976, after the restoration of summer time, and concludes that there were 661 more deaths on the roads that year, between April and October, than in 1975 .
In a report published in September 2014, the European Commission, which reviewed several studies on the subject, notes “often contradictory results”some reports “suggesting that the change improves road safety”, thanks to better visibility at certain times of the year and of the day (as explained in a Scottish study in 2010), other “demonstrating a potential increase in road accidents due to sleep disturbance”.
This year, however, Road Safety has decided to emphasize the importance of being visible on the public highway, with “retro-reflective devices (vest, armband, gloves, strips on the backpack, schoolbag, etc.)” just before the time change. The number of accidents involving a pedestrian indeed increases recurrently by 42% in November, compared to October, according to data from the National Interministerial Observatory for Road Safety collected between 2015 and 2019.
4. Consequences on health?
In 2008, a Swedish study published in the New England Journal of Medicinebased on the country’s statistics between 1987 and 2006, found “a statistically significant increase in the risk of heart attack” in the week following the change of time, in particular during the transition to summer time.
A September 2015 study, conducted by the European Commission, writes that “health can be affected by the change in the body’s biorhythm, with possible sleep and mood disturbances”.
But just as winter depression cannot be explained by a causal link (rather tenuous from a scientific point of view) between lack of light and low morale, the disturbances induced by the time change cannot be explained by the present time only by assumptions. However, the Commission concludes that “the evidence regarding the overall health effects (i.e. the balancing of the alleged negative and positive effects) is inconclusive”.
In 1997, a Senate report assured that “the medical world [restait] very divided on the existence of problems attributable to summer time”. True or fantasized, the medical risk has in any case been integrated by potential patients: “19% of physicians [faisaient] state of an increase in the consumption of drugs and particularly tranquilizers at the time of the time change ». In an OpinionWay survey for UnderstandingChoisir, published in October 2015, 75% of respondents said that the time change had a negative impact on “sleep, food or mood”.