Daylight saving time and sunrise and sunset
What daylight saving time really changes (and what it does not), when clocks change in Europe and North America, and how it shifts your mornings and evenings.
Twice a year, in most of Europe and North America, clocks jump by an hour. The sun does not care: it rises and sets exactly as before. What changes is the number on the clock when it happens.
When the clocks change
| Region | Clocks go forward | Clocks go back |
|---|---|---|
| EU, UK, most of Europe | Last Sunday in March, 01:00 UTC | Last Sunday in October, 01:00 UTC |
| USA and Canada (most areas) | Second Sunday in March, 2:00 local time | First Sunday in November, 2:00 local time |
| Southern Hemisphere (e.g. Sydney) | First Sunday in October | First Sunday in April |
Many countries do not change their clocks at all, including most of Asia and Africa, Iceland, Hawaii and most of Arizona. In the Southern Hemisphere the change runs the other way round because the seasons are reversed.
What it looks like in real numbers
On the weekend of the spring change, sunrise jumps from early to about an hour later overnight. In Ljubljana, where the change is on the last Sunday in March:
| Date | Civil dawn | Sunrise | Solar noon | Sunset | Day length |
|---|---|---|---|---|---|
| Mar 25, 2026 | 05:26 | 05:56 | 12:08 | 18:21 | 12 h 25 min |
| Mar 26, 2026 | 05:24 | 05:54 | 12:08 | 18:22 | 12 h 29 min |
| Mar 27, 2026 | 05:22 | 05:52 | 12:07 | 18:24 | 12 h 32 min |
| Mar 28, 2026 | 05:20 | 05:50 | 12:07 | 18:25 | 12 h 35 min |
| Mar 29, 2026 | 06:18 | 06:48 | 13:07 | 19:26 | 12 h 38 min |
| Mar 30, 2026 | 06:16 | 06:46 | 13:06 | 19:28 | 12 h 42 min |
| Mar 31, 2026 | 06:14 | 06:44 | 13:06 | 19:29 | 12 h 45 min |
The day length column changes smoothly by about three minutes a day, as it always does in spring. Only the clock times jump.
Why we have it
The idea is to move daylight from early morning, when many people are asleep, into the evening, when they are awake. In summer at mid-latitudes the sun would otherwise rise around 4:00 to 5:00 and set around 19:00 to 20:00. With summer time, sunset moves to around 20:00 to 21:00, which people use for outdoor activities.
The energy savings that were the original motivation are small or unclear today, and the change itself disrupts sleep for a few days. That is why the debate about ending it continues on both sides of the Atlantic.
Late summer sunsets in western Europe
Clock time zones do not follow the sun closely. Spain, France and the Benelux countries use Central European Time, which is based on 15° E, although they lie far to the west. Add summer time, and the sun in Madrid or western France is almost two hours “behind” the clock: solar noon in Madrid in summer is around 14:15, and sunsets come after 21:45 around the June solstice.
How Heliotempo handles it
All times on Heliotempo are shown in the local time of the place, including daylight saving time when it applies. The time zone rules come from the IANA time zone database that your browser uses. Every city page lists the dates of the clock changes for the current year, and the day length chart shows the jumps as steps in the sunrise and sunset curves.
Frequently asked questions
Does daylight saving time give us more daylight?
No. The amount of daylight is set by the sun and your latitude. Daylight saving time only moves the clock, so that sunrise and sunset happen an hour later by the clock. Mornings become darker and evenings lighter.
When do the clocks change in Europe?
In the European Union, the UK and most of the rest of Europe, clocks go forward one hour at 01:00 UTC on the last Sunday in March and back at 01:00 UTC on the last Sunday in October.
When do the clocks change in the United States?
Clocks go forward at 2:00 a.m. local time on the second Sunday in March and back at 2:00 a.m. on the first Sunday in November. Hawaii and most of Arizona do not use daylight saving time.
Is the EU abolishing daylight saving time?
The European Parliament voted in 2019 to end seasonal clock changes, but member states have not agreed on how to do it, so the clocks still change twice a year.