Every spring, when the days begin to lengthen, the time also comes to Adjust clocks for summer time in SpainIt's a simple gesture, very much part of our routine, but it still raises recurring questions: whether we move the clocks forward or backward, how much daylight do we gain in the evenings, or how long does it take us to adapt?
Although we have lived with this practice for decades, The time change continues to be at the center of political, social and scientific debateWhile a large part of the public is calling for an end to these two annual adjustments, sleep and chronobiology experts are warning of their effects on health, and European institutions have yet to reach a final decision.
When does the clocks change to summer time?
El The switch to summer time in Spain always takes place on the last Sunday of March.In practice, this means that the transition takes place in the early hours of the Saturday, March 28 to Sunday, March 29, in accordance with the schedule set by the European Union and included in Spanish regulations.
In mainland Spain and the Balearic Islands, At 2:00 in the morning, the clocks are moved forward to 3:00.In the Canary Islands, where the official time is sixty minutes behind that of the mainland, The adjustment is made between 1:00 and 2:00That night, therefore, the day has only 23 hours and sleep one hour less.
This pattern is repeated every year: March marks the start of summer time y October, the return to winter timealways on the last Sunday of each of those months. The regulation is set out in Royal Decree 236/2002 and in Order PCM/186/2022, which publishes the official calendar of time changes for the period 2022-2026.
The immediate consequence of the advance is that, starting that Sunday, Sunrise is delayed on the clock, but sunset arrives later.In other words, you gain light in the afternoon at the expense of sacrificing clarity in the early morning, something that many people notice very clearly at the beginning of spring.
How the time change is applied and which devices adjust automatically
In practice, the time change causes fewer headaches than it did a few decades ago because Most electronic devices update automaticallyMobile phones, tablets, computers, smartwatches, and televisions are synchronized through systems such as... Network Time Protocol (NTP), which adjusts the time based on the network's time servers.
Still, It's advisable to check analog clocks, household appliances, or devices without a connection.Appliances like ovens, microwaves, or traditional alarm clocks require manual adjustment. It's in these small details that the typical Monday morning confusion often arises: arriving an hour early—or late—to an appointment because you kept looking at the wrong clock.
In general terms, European coordination means that The change will be implemented in a synchronized manner in virtually all countries of the European Unionas well as other regions of the world that maintain this system, such as much of North America, Chile or some areas of Australia.
Why did the clocks start changing and what is their purpose?
The modern origin of daylight saving time is closely linked to the idea of Make better use of natural light and save energy. During the World War ISeveral European countries began to advance or delay their clocks to reduce fuel consumption and adjust activity to daylight hours.
In Spain, the measure was applied intermittently from 1918. with various experiments with summer and winter time between the 1920s and 1940sHowever, stable implementation came later: in 1974, in the midst of the oil crisisThe country revived the time change with the same stated objective, energy saving, and it has been maintained continuously ever since.
The initial logic was simple: shift the workday towards daylight hours to reduce artificial lighting and other associated energy consumption. This philosophy consolidated the annual double change in March and October, later extended and harmonized within the European Union through specific directives.
Over the years, however, The energy argument has been losing strengthSeveral studies suggest that The actual savings are minimal or even non-existent, especially in a context influenced by many other factors: air conditioning, new consumption habits, electronic equipment, or labor structures very different from those of the seventies.
Impact of daylight saving time on health and biological rhythm
Beyond the organization of the clock, The main focus of discussion today is on the effects of the time change on the bodyThe scientific community specializing in sleep and chronobiology insists that these adjustments are not harmless, especially when they involve losing an hour of rest all at once.
The coordinator of the Chronobiology working group of the Spanish Sleep Society explains that The time change acts as a kind of "mini jet lag"The biological clock is forced to abruptly synchronize with social schedules that are moving earlier, generating a temporary loss of alignment between our internal rhythm and the environmentThis imbalance, although not as intense as that which occurs on an intercontinental trip, can take several days to correct itself.
In those early days, Sleep disturbances, fatigue, and concentration problems are common.Some population studies have observed occasional increases in traffic accidents, cardiovascular problems, or sleep disorders in the days immediately following the change, especially during the switch to summer time, when sleep is reduced by one hour.
Researchers in chronobiology and sleep also point out symptoms similar to those of jet lagirritability, daytime sleepiness, difficulty falling asleep at night or digestive disturbances (hunger at unusual times, feeling full, or lack of appetite at regular meals). These effects are usually temporary, but they don't affect everyone equally.
Tips to better adapt to the new schedule
Sleep specialists recommend Prepare for the time change gradually In the days leading up to it, especially in homes with children or particularly vulnerable people, a simple guideline is to move the daily routine forward a little: go to sleep, eat, or exercise 15-20 minutes earlier each day for several days before the official adjustment.
Another key is to take care of the light exposureNatural light is the main synchronizer of the biological clock, so Take advantage of the early hours of the day to be outdoors It helps the body adjust to the new schedule. Conversely, maintaining prolonged contact with bright screens before bed (mobile phones, tablets, computers) can further delay falling asleep.
Regarding lifestyle, maintain regular sleep and meal times It is often more important in the long run than the time change itself. Neuroscientists specializing in sleep insist that a stable sleep-wake routine, to the extent possible compatible with our chronotype (earlier or more nocturnal), has more weight on general health than the fact of advancing or delaying the clock twice a year.
It is also worth remembering that work dynamics, school schedules, and daily obligations They have a very significant impact on how we rest. Many experts point out that the real challenge lies in rationalize social schedules to bring them closer to the biological rhythm and the natural light cycle, especially in countries like Spain, where the time zone is already misaligned with the sun.
Spain and the time zone: a fundamental mismatch
The debate about changing the clocks intersects with another fundamental issue: The time zone in Spain does not coincide with its geographical positionUntil 1940, official time was based on the Greenwich Meridian (GMT+0), shared with the United Kingdom and Portugal. That year, the Franco regime decided to advance it by one hour, aligning it with Central Europe.
Since then, Much of Spain shares the same time zone as cities like Berlin or BelgradeDespite being located much further west, only the Canary Islands maintain a different time zone, one hour behind the mainland, being closer to the prime meridian. This difference means that, even in what is called standard time (winter time), Many social activities take place when, according to the sun, it would still be "nighttime".
This chronic misalignment between social time (the time measured by clocks) and solar time is known as chronodisruptionChronobiology experts link it to increased risk of metabolic and cardiovascular diseases, cognitive decline, premature aging and even a possible increase in the incidence of certain types of cancer.
The situation is especially striking in extreme locations such as Galiciawhere in the middle of summer the Sunset can occur after ten o'clock at night with summer time. If that time were maintained all year round, in winter the sun would rise very late, with long, dark mornings that would worsen the mismatch between clock and biological rhythm.
Summer or winter time? What the experts say
In public discourse, the debate is often simplified into Choose between summer time or winter timeMost surveys, such as those from the Center for Sociological Research (CIS), indicate that a A large part of the population prefers permanent summer timeassociating it with long afternoons, more outdoor leisure and a feeling of more productive days.
However, Scientific societies and sleep experts are quite clearly in favor of winter time.which they consider the "standard time" or the one most aligned with the solar cycle. Their arguments are based on the fact that A permanently earlier schedule exacerbates chronodisruptionespecially in the cold months, with very late sunrises.
Some researchers admit, however, that There is no perfect solution.There are voices that maintain that Maintaining a fixed schedule, even if it's not ideal, could be less harmful than subjecting the body to two abrupt changes a year.Others, however, remember that A bad schedule maintained indefinitely could have deeper negative effects than the specific adjustments in March and October.
Amid these positions, there is some consensus on one point: The key is to minimize the gap between our biological clock and social schedulesThis involves choosing the time zone that best suits our geographical location, reviewing work and school schedules, and promoting habits that respect natural sleep-wake rhythms.
Individual chronotypes also come into play. There are Some people are more morning-oriented, while others are more evening-oriented due to biological predisposition.Forcing someone to constantly adapt to a schedule far removed from their chronotype can hinder rest and worsen sleep quality, with the consequent impact on daily well-being.
Social support and political debate on ending daylight saving time
In recent years, surveys reflect that Most Spaniards would prefer to end the double time changeMany citizens complain that it gets dark too early in winter and support keeping summer time permanently, even though the scientific community does not see it as the best option.
On the political front, the issue has reached both the Spanish government as well as European institutions. President Pedro Sánchez has publicly questioned the current usefulness of the time change, alluding to the fact that It offers little energy saving and has negative effects on health and daily life.However, Spain cannot unilaterally modify the system without coordinating with its EU partners.
In 2018, following a public consultation in which Millions of European citizens overwhelmingly voted in favor of eliminating daylight saving time.The European Commission proposed ending these seasonal adjustments. The European Parliament even set 2021 as the deadline for the final change. However, the lack of consensus among member states, especially regarding what schedule to definitely keep, slowed the process.
In the Spanish case, a expert committee created in 2019 to analyze the issue, he concluded that There was no clear consensus regarding which time to adopt permanently. Without a firm position at the national level and without agreement within the Council and the European Parliament, the matter remains, for the moment, at a standstill.
The European calendar: time change guaranteed, for now, until 2031
Despite the political stalemate, the administrative machinery has continued its course. The European Commission has already set the timetable for changing the clocks until 2031.with specific dates for switching to summer time and returning to winter time each year. These are always the last Sundays of March and October, with slight variations depending on the calendar.
That means that, unless otherwise agreed, The time change system will remain in effect for at least the next few yearsIn parallel, Brussels has commissioned a new technical report to reassess the advantages and disadvantages of the different options, with the intention of reactivating the political debate when that analysis is available.
In Spain, Official State Bulletin (BOE) Every five years, the order with the national calendar of time changes is published. The current one, which covers the period 2022-2026, sets the last adjustment scheduled for October 2026It is expected that this order will be updated to align with the European timetable 2027-2031, unless the EU decides to end the system before that date.
Platforms like the Time Use Initiative and other entities specializing in time use continue to press for accelerate decision-making, remembering that there is broad public support and a scientific consensus on the costs of changing the clocksTheir campaigns insist that the debate over broadcasting time is part of a broader context of rationalization of work, study and personal life times in all Europe.
With all this context, the upcoming time change brings the same questions back to the table every year, but with an increasingly complex background. Spain will continue to move the clocks forward and backward until Europe agrees on a common positionAnd in that interval the focus shifts to how to minimize its effects: taking advantage of natural light, taking care of sleep habits and moving towards more reasonable social schedules, more in tune with our biological clock and the cycle of the sun than with the simple hands of the clock.
