When do the clocks go back and does it save energy? Experts say the difference is negligible

It’s that time of year again: on Sunday 27 October, Europeans will be dialling their clocks back one hour. 

The end of Daylight Savings Times (DST) means an extra hour in bed tomorrow and lighter mornings. On the flip side, darkness will draw in quicker in the evenings, with sunset in London at a dispiriting 4.42pm on Sunday. 

For years, the EU has been debating whether to get rid of DST altogether - partly given the limited energy savings of changing the clocks.

In 2018, the European Commission officially proposed the abolition of the twice-a-year clock changes and Parliament supported that proposal in a resolution in March 2019. It came after a public consultation by the Commission showed strong support from 4.6 million EU citizens for scrapping it.

The changes were meant to come in by 2021 but have since been stuck with the EU's co-legislator, the Council of the European Union, representing the 27 Member States.

The Member States are divided over the practical implementation of the change.

One of the biggest questions yet to be conclusively answered is whether DST actually reduces energy consumption.

Several studies have found that DST’s impact on the environment is negligible, or even negative. So is time up for seasonal clock changes?

Why was Daylight Savings Time introduced in Europe?

In the UK and Germany, DST was introduced to conserve coal in World War I. It was abolished when the war ended but returned during the 1980s when the necessity to save resources returned, driven by the global oil crisis.

Since 2002, all countries in the European Union - except for Iceland - have had to adjust their clocks on the last Sunday of March and October.

Does Daylight Savings Time reduce energy consumption?

Several studies in Europe and the US show DST has very little effect on energy conservation.

In Italy, the Italian Society of Environmental Medicine calculated that even postponing the clock change from the end of October to the end of November would save the country €70 million in fuel bills.

A study by researchers at Charles University in Prague used hourly data from 2010 to 2017 to find that DST in Slovakia resulted in estimated energy savings equal to just 0.8 per cent of annual electricity consumption.

In the US, a study conducted by the Department of Transportation in 1975 showed that Daylight Savings cut around 1 per cent of the country’s energy usage.

This insignificant saving might, in part, be because many people in the US get out of bed before 7am. Much of the energy saved by not having the lights on in the evening was offset by having them on in the morning.

A 1993 publication on fuel (gas and coal) consumption in France and Belgium observed an increase in fuel consumption with DST due to extra driving. This was corroborated by studies on pollutant dispersion.

Instead, natural time zones as close as possible to solar time likely align daily light and temperature curves better with our schedules.

This could lead to energy savings on early morning industrial and other lighting, early morning heating during the colder months as people leave for work an hour later and less air conditioning needed in the car on the commute after work and in the evening at home.

Will Europe stop changing its clocks?

In 2023, experts asked the Council of the European Union to add the topic of abolishing clock changes to its agenda.

Those in favour of the proposal had hoped the issue would be addressed before June’s EU Parliament elections.

In March, chair of the European Parliament internal market committee, German Green MEP Anna Cavazzini, urged countries to finally reach a common position on the matter.

"At the end of this legislative period, it is unfortunately clear that the abolition of the time change has become a non-starter in the Council," she said.

"In order to avoid further frustration, the Council must finally untie the Gordian knot of the member states' divergent opinions and take a position.

That didn’t prove possible, however, and the DST issue appears to be back on the backburner.

That’s despite a campaign from the The Time Use Initiative, which previously launched an EU Manifesto on Time Policies including twelve necessary changes Europe needs to make to assure the “right to time” to all the Europeans.

“The EU must react to the negative impact of misaligned clocks by pushing to implement permanent time zones as close as possible to solar time (natural time) in Europe,” the manifesto reads.

“Misaligned clocks that make schedules start earlier than the natural day-night cycle increase sleep deprivation and cause negative effects on human health, economy, and safety. The EU has the power to change this.”