Why Spain Still Changes the Clocks—and What Would Happen If It Stopped

Every autumn, Spain turns its clocks back and gains an extra hour overnight. Every spring, it gives that hour back. The familiar explanation is “to save energy”—but that is only part of the story, and not a particularly strong description of what daylight saving achieves today.

To understand why Spain still does it, you need to separate three questions: why seasonal clock changes began, why EU rules still require them, and which time Spain should keep if the changes end.

What changing the clocks actually does

Daylight saving time, also called summer time, means setting the clock one hour ahead of standard time for part of the year. Standard time is the underlying time used outside that seasonal adjustment—often called winter time in Spain.

The purpose is to move daylight into the evening as measured by the clock.

Imagine that sunset would normally occur at 19:00. Advance the clocks by an hour, and the same sunset is labelled 20:00. If you finish work at 17:00 under either arrangement, summer time leaves more daylight after work.

But there is a trade-off: sunrise also appears an hour later.

Changing the clocks does not create daylight. It changes how daylight lines up with your daily schedule.

Spain follows the EU schedule: clocks advance on the last Sunday in March and return to standard time on the last Sunday in October.

In 2026, the autumn change falls on Sunday, October 25:

That repeated hour makes the night an hour longer. The dates are set out in the EU’s published timetable.

Who came up with the idea?

Franklin’s joke was about waking earlier—not changing clocks

Benjamin Franklin often gets credit for daylight saving time, but that confuses two different ideas.

In a 1784 satirical essay, written while he was in Paris, Franklin suggested that people could save candles by getting up earlier and using morning sunlight. He was not proposing a seasonal change to the clocks.

The first well-documented proposal for a seasonal clock adjustment came from George Vernon Hudson, a New Zealand entomologist—a scientist who studies insects—in 1895. British builder William Willett independently promoted a similar idea in 1907.

The useful distinction is:

• Franklin joked about changing people’s habits.
• Hudson proposed changing the clocks seasonally.
• Willett campaigned to make the idea public policy.

The Franklin Institute’s historical account explains why Franklin’s role is often overstated.

World War I turned an idea into national policy

Some Canadian communities experimented with seasonal clock changes before World War I. But the war was the turning point for adoption by entire countries.

Germany and Austria-Hungary introduced daylight saving nationally in 1916, aiming to conserve fuel. Britain followed that May.

The reasoning was straightforward: if people had more daylight during their evening activities, they would need less artificial lighting. In an era when lighting depended on gas and coal-fired electricity, that could reduce demand for fuel needed for the war effort.

So World War I did not produce the original idea. It supplied the urgency that persuaded governments to act.

Did daylight saving really save coal?

The mechanism was plausible. Someone who finished work and went to bed at the same clock times could spend less of the evening under artificial light. Utilities might then burn less coal to provide that lighting.

What is much harder to establish is how much fuel the change actually saved.

A later account in the UK Parliament reported a committee estimate of a 20% reduction in electricity used for lighting, equivalent to approximately 1% of annual coal use. Those figures describe very different things: a large percentage saving in one use of electricity is not a large percentage saving in all fuel consumption.

Germany’s Deutsches Uhrenmuseum has also noted that a reduction in coal and gas use attributable to the clock change could not be demonstrated even in 1916.

Wartime conditions make the question especially difficult. Industrial production, fuel restrictions and daily routines were all changing at once. Separating the effect of the clocks from those other influences is not simple.

Saving coal was the wartime rationale for daylight saving—not a firmly established, large-scale result.

The argument for reduced evening lighting is documented in Britain’s 1916 parliamentary debate.

Does it save energy today?

Sometimes a little, but not reliably.

Modern homes use energy very differently from homes in 1916. Efficient LED lighting requires much less electricity, so avoiding an hour of lighting offers a smaller saving. Meanwhile, heating and air conditioning can outweigh that benefit.

The possible effects pull in different directions:

A review of 44 studies found an average electricity saving of 0.34% on days when daylight saving applied. However, the estimate fell close to zero when the researchers gave greater weight to the studies they considered most reliable.

The European Commission’s assessment described overall energy savings as marginal, with results varying by location.

Indiana shows why the answer can even be negative

In 2006, much of Indiana began observing daylight saving time. That gave researchers Matthew Kotchen and Laura Grant an opportunity to compare household electricity use before and after the change.

Using more than 7 million monthly billing observations from southern Indiana, they estimated that daylight saving:

• Increased residential electricity use by about 1% overall.
• Produced its largest estimated increases in autumn, at 2–4%.

Their explanation was a trade-off: lighting savings were outweighed by greater heating and cooling demand.

There is an important evidence distinction here. The bills supported the estimate of increased electricity use; household-energy simulations helped explain the mechanism. The researchers did not directly measure each household’s electricity use separately for lighting, heating and cooling.

The Indiana study is strong evidence for the households it examined—not proof that daylight saving increases consumption everywhere.

The broader lesson is that saving electricity on lighting is not the same as saving energy overall.

Didn’t the EU vote to stop changing the clocks?

Yes—but a parliamentary vote was not the same as a completed law.

In 2019, the European Parliament supported ending seasonal clock changes by 2021. For that proposal to become law, it also needed agreement from the Council of the European Union, the body in which national governments participate in EU lawmaking.

Member-state governments have not agreed a common position, so the proposal remains blocked. The Council’s explanation of the process sets out why the existing rules remain in force.

The central difficulty is what happens after the changes stop. Countries would need to choose which time to keep and coordinate with their neighbours.

Without coordination, Europe could end up with a patchwork of arrangements that complicates transport timetables, cross-border work and trade.

Spain has called for negotiations to resume, but that does not itself change the law. The existing EU timetable still governs Spain’s clock changes in 2026.

Which is better for sleep: permanent summer or winter time?

For sleep and the timing of your body’s daily rhythms, major sleep-science organisations generally recommend permanent standard time—Spain’s winter time—rather than permanent summer time.

The key concept is your circadian rhythm: the roughly 24-hour internal cycle that helps regulate when you feel alert or sleepy. Light is an important signal that keeps this internal clock aligned with the outside world.

Morning light and evening light do different jobs

Morning light helps set your body clock. Light later in the evening can push sleep timing later.

Under permanent summer time:

• Winter sunrise would appear one hour later on the clock.
• You would have less morning daylight before a fixed work or school start.
• Daylight would extend later into the afternoon or evening.

Standard time generally offers a better match between daylight and the body’s daily cycle. That is why organisations including the European Sleep Research Society, the European Biological Rhythms Society and the American Academy of Sleep Medicine favour it.

But the certainty needs care. Evidence about the short-term disruption caused by changing the clocks is stronger than direct evidence comparing the long-term health effects of living permanently under each option.

Permanent standard time is therefore the prevailing sleep-science recommendation—not a guarantee that everyone would sleep better, or a claim that evening daylight has no benefits.

Is Spain in the “wrong” time zone?

This is related to daylight saving, but it is a separate question.

Mainland Spain uses Central European Time in winter, one hour ahead of Portugal and the UK, even though much of Spain lies at similar longitudes. Longitude is your east–west position on Earth; it helps determine when the sun reaches its highest point locally.

Calling Spain’s time zone “wrong” is shorthand for a mismatch between the clock and the sun. It is not a literal rule: legal time zones also reflect political and practical choices.

What happened under Franco?

Under Franco’s government, a March 1940 order advanced Spain’s clocks by an hour.

It is often said that Franco did this “to match Hitler’s Germany.” However, the original order said the change would bring Spain’s time into line with other European countries; it did not specifically name Germany.

The historical clock change is clear. That particular account of its motive is more confident than the document supports.

Would moving to Portugal’s time give you more sleep?

Not automatically. A clock label cannot add an hour to the night.

Imagine two possibilities:

1. The clock and every schedule move together. A former 09:00 start becomes 08:00, and meals and bedtimes shift similarly. You still do everything at the same actual moment relative to the sun.
2. The clock changes, but work still starts at 09:00. Your start is now an hour later relative to the sun, potentially giving you more daylight before work.

The second arrangement could improve the alignment between daylight and social schedules. Whether it increases sleep depends on what happens to bedtimes, working hours and other routines.

A study comparing older adults in western Spain and Portugal found some more favourable measures of circadian regularity in the Portuguese group, but similar sleep durations. It cannot establish what would happen if Spain as a whole changed time zones.

The bottom line

Spain still changes the clocks because EU rules remain in force, not because modern energy savings have been convincingly established.

The choices ahead are distinct: stop the twice-yearly switches, decide whether to retain standard or summer time, and consider whether mainland Spain’s underlying time zone should change.

For sleep, the prevailing scientific recommendation favours permanent standard time. But any wider reform needs to look beyond the clock face. What ultimately matters is when daylight reaches you—and when work, school and daily life require you to be awake.