When do the clocks change?

Every year in the European Union the clocks change on the last Sunday of March, to switch to daylight saving (summer) time, and on the last Sunday of October, to go back to standard (winter) time.

Summer time 2049 (CEST, GMT+2)

Summer time starts on 28 March 2049

Summer time (daylight saving time) is when the clocks go forward one hour in spring, which means that at 2 am it becomes 3 am. In the European Union, summer time starts on the last Sunday of March and ends on the last Sunday of October.

The aim of summer time is to make the most of natural daylight and reduce electricity consumption. By moving the clocks forward one hour in spring, daylight lasts longer in the evening, which saves energy on lighting and heating.

Summer time is applied in most European countries and elsewhere in the world. However, some countries do not change their clocks and keep the same time all year round.

Winter time 2049 (CET, GMT+1)

Winter time starts on 31 October 2049

Winter time (standard time) is when the clocks go back one hour in autumn, which means that at 3 am it becomes 2 am. In the European Union, winter time starts on the last Sunday of October and ends on the last Sunday of March.

The aim of winter time is to adapt the clocks to the change of season and make better use of daylight. By moving the clocks back one hour in autumn, daylight lasts longer in the morning, which saves energy on lighting and heating.

Winter time is applied in most European countries and elsewhere in the world. However, some countries do not change their clocks and keep the same time all year round.

Clock changes in other years

Why do we change the clocks in spring?

The clock change in March, known as summer time or daylight saving time, is applied mainly to make better use of natural daylight during the spring and summer months. These are the main reasons:

1. Energy saving

• The original idea behind the clock change is to reduce energy consumption, especially the electricity used for lighting. By moving the clock forward one hour, evenings have more daylight, which reduces the use of artificial lighting in homes and businesses.
• Although the energy saving today is smaller because of the widespread use of efficient technologies (such as LED lighting), it remains the historical justification.

2. Making the most of sunlight

• In spring and summer the days are longer, and the clock change lets people enjoy more hours of daylight at the end of the day. This can encourage outdoor activities and reduce electricity consumption.

3. International coordination

• Many countries, especially in Europe and North America, adopt summer time to keep business, transport and communication schedules in sync between regions. This makes trade and international coordination easier.

4. History and tradition

• The clock change became popular during the First and Second World Wars as a way to save resources. Although circumstances have changed, many countries have kept the practice out of habit.

5. Impact on the economy and lifestyle

• Some argue that summer time benefits sectors such as retail, tourism and hospitality, since people tend to go out more and spend more money when there is more daylight at the end of the day.

Criticism and debate

• In recent years the clock change has been the subject of debate. Some studies suggest that the energy saving is minimal and that the change can harm health by disrupting circadian rhythms and causing sleep disorders.
• The European Union, for instance, has considered scrapping the clock change, leaving each country to decide whether to keep summer or winter time permanently.

In short, the clock change in March is made mainly to make better use of daylight and reduce energy consumption, although its usefulness today is disputed.

Why do we change the clocks in autumn?

The autumn clock change, known as winter time, consists of putting the clocks back one hour (usually on the last Sunday of October in Europe, or the first Sunday of November in some countries such as the United States). This change has several reasons and effects:

1. Returning to standard time

• During summer time the clocks are moved forward one hour to make use of daylight. In autumn they are put back to return to standard time, which is more in line with the natural cycle of sunlight during the winter months.

2. Energy saving

• Although the original aim of summer time was to save energy, in autumn the clocks go back to prevent sunrise from being too late in winter. This makes mornings brighter, which can reduce electricity use in the early hours of the day.

3. Adapting to shorter days

• In autumn and winter the days are shorter and there are fewer hours of daylight. By putting the clock back, mornings are brighter, which can help with activities such as going to work or school.

4. Impact on health and well-being

• The autumn clock change can be less disruptive to sleep than the spring one, since gaining an hour of sleep is generally easier than losing one. However, some people may still experience disturbances to their circadian rhythm.

5. International coordination

• As in spring, the autumn clock change is made in many countries to keep business, transport and communication schedules in sync. This is particularly important in regions such as the European Union, where many countries change their clocks at the same time.

6. Debate about its usefulness

• As with summer time, the autumn clock change has been questioned. Some argue that the energy saving is minimal and that the negative effects on health and well-being may outweigh the benefits.
• The European Union, for instance, has debated abolishing the clock change and letting each country choose whether to keep summer or winter time permanently.

Effects of the autumn clock change

• More light in the morning: by putting the clock back, the sun rises earlier, which can help morning activities.
• Less light in the evening: it gets dark earlier in the evening, which can affect mood and reduce outdoor activities.

In short, the autumn clock change is made to return to standard time and adapt to the shorter days of winter, although its usefulness and effects are still debated.

Which countries change their clocks in March and October?

Switching to summer time on the last Sunday of March is common practice in many European countries. This is the list of countries that traditionally make this change:

1. Austria
2. Belgium
3. Bulgaria
4. Croatia
5. Czech Republic
6. Denmark
7. Estonia
8. Finland
9. France
10. Germany
11. Greece
12. Hungary
13. Ireland
14. Italy
15. Latvia
16. Lithuania
17. Luxembourg
18. Malta
19. Netherlands
20. Norway*
21. Poland
22. Portugal
23. Romania
24. Slovakia
25. Slovenia
26. Spain
27. Sweden
28. Switzerland*

These countries are members of the European Union (*except Switzerland and Norway) and follow the EU Directive that sets the switch to summer time on the last Sunday of March and the return to winter time on the last Sunday of October. However, the EU has been considering abolishing this practice, so the dates could change in the future.

Which European countries do not change their clocks in March and October?

In Europe most countries switch between winter and summer time following the European Union Directive that sets the change on the last Sunday of March (summer time) and the last Sunday of October (winter time). There are, however, some exceptions. These are the European countries that do not change their clocks:

1. Iceland

Iceland does not change its clocks and keeps GMT (UTC+0) all year round. Despite its location close to the Arctic Circle, where the differences in daylight hours are extreme, the country decided not to adopt summer time.

2. Belarus

Belarus abandoned the clock change in 2011 and decided to stay on summer time (UTC+3) all year round.

3. Russia

Russia abolished the clock change in 2014 and adopted permanent standard time (UTC+3 in Moscow). The country had previously experimented with permanent summer time, but decided to go back to standard time.

4. Turkey

Turkey stopped changing its clocks in 2016 and decided to stay on summer time (UTC+3) all year round.

5. Armenia

Armenia does not change its clocks and keeps standard time (UTC+4) all year round.

6. Azerbaijan

Azerbaijan abolished the clock change in 2016 and stays on standard time (UTC+4).

7. Georgia

Georgia does not change its clocks and keeps standard time (UTC+4).

8. Kazakhstan (European part)

Kazakhstan, although most of its territory is in Asia, has a small part in Europe. The country does not change its clocks and keeps standard time (UTC+5).

In short, the European countries that do not change their clocks are mainly Iceland, Belarus, Russia, Turkey, Armenia, Azerbaijan, Georgia and Kazakhstan (in its European part).