Reykjavik sits at roughly 21°57′W, a longitude that would normally suggest UTC−1. Iceland uses Greenwich Mean Time (GMT), UTC+0, year-round anyway. The country made this choice deliberately, and it has stuck with it since 1968, when Iceland abolished daylight saving time and committed to permanent GMT. That decision says more about Icelandic priorities than about geography.
Why does Iceland use GMT year-round instead of UTC−1?
A time zone is not a natural law. It is a political agreement about which clock you want to live by. Iceland's longitude places it far west of the prime meridian. The 0° line runs through Greenwich, London, and Iceland sits mostly between 13°W and 24°W. If Iceland followed the textbook rule of one hour per 15 degrees of longitude, it would sit in UTC−1, the same zone as the Azores.
But Iceland does not follow the textbook. It follows Europe.
The country's economy, aviation links and cultural ties point east across the North Atlantic to the United Kingdom and mainland Europe. London is about 1,900 kilometres from Reykjavik, and the two capitals share a flight time of around three hours. When it is noon in London, it is noon in Reykjavik, every day of the year. That synchronisation matters more than the sun's position overhead.
What happened to Iceland's clocks in 1968?
Iceland did not always keep GMT year-round. Before 1968, the country used standard time in winter and advanced its clocks by one hour in summer, following the same daylight saving pattern as much of Europe. That changed with a parliamentary decision to stop the seasonal clock changes altogether.
The motivation was practical. Iceland's high latitude, between roughly 63°N and 66°N, creates extreme seasonal variation in natural light. In Reykjavik, midsummer brings nearly 21 hours of brightness, with the sun barely dipping below the horizon. Midwinter offers only about 4 hours. When natural light is already this skewed, shifting clocks by an hour does little to change how people live. An extra hour of evening brightness in summer is meaningless when the sun barely sets, and an extra hour of morning light in winter is wasted when most people are still asleep.
So Iceland chose a permanent time zone. The country has not touched its clocks since.
What Iceland's fixed GMT means for daily life
The most visible consequence is that Icelanders never experience the biannual disruption that affects the UK and most of Europe. No lost hour in spring. No gained hour in autumn. No confusion about whether the clocks go forward or back.
But the lack of daylight saving does create a quirk. Because Iceland stays on GMT while the UK moves to British Summer Time (BST, GMT+1) in summer, the two countries are on the same clock for roughly half the year and an hour apart for the other half. From late March to late October, when it is 10:00 in London, it is 09:00 in Reykjavik. This matters for business calls, flight schedules and anyone booking a trip.
In winter, Iceland and the UK share the same time. In summer, Iceland is one hour behind the UK. This surprises many visitors, who assume the two countries share a time zone year-round because of their close ties.
How does Iceland cope with extreme seasonal light on a fixed clock?
Icelanders have effectively accepted a divorce between their clocks and the sun. The clocks do not adjust for the season. The sun simply does what it does.
This is the opposite of the situation in West African nations on GMT, which sit near the equator where daylight varies by only about 30 minutes across the entire year. Iceland sits far north, where natural light swings wildly by season. Yet both regions share the same fixed time zone, and both have decided that seasonal clock changes are not worth the trouble.
The result is a country where "lunchtime" in winter may feel like dawn, and where "evening" in summer may look like late afternoon. Visitors adjust quickly, but the experience is a reminder that time zones are conventions, not cosmic facts.
How does Iceland's GMT choice compare to its neighbours?
Iceland is not alone in making a politically motivated time zone choice. Portugal, Ireland and the Canary Islands all use time zones that reflect their political and economic ties as much as their longitude. The United Kingdom itself, which defines GMT, sits west of the prime meridian for most of its landmass, yet uses UTC+0 in winter.
The key difference: the UK, Ireland and most of Europe still observe daylight saving time. Iceland does not. This makes Iceland the only European nation that uses GMT year-round without any seasonal adjustment.
For anyone scheduling calls or travel, the rule of thumb is simple. Check whether the UK is on GMT or BST. If the UK is on GMT, Iceland is the same time. If the UK is on BST, Iceland is one hour behind.
What should travellers and remote workers know about Iceland's time zone?
If you are planning a trip to Iceland or working with Icelandic colleagues, the time zone is easy to manage once you know the pattern. From late October to late March, Iceland matches the UK exactly. From late March to late October, Iceland is one hour behind the UK, and therefore one hour behind London, Dublin and Lisbon.
Do not assume that Iceland follows the same clock as the UK in summer. That one-hour difference has caught out many a remote worker who dialled in an hour early, and many a traveller who booked a flight expecting the same time zone.
The safest approach is to check a reliable GMT time reference before making any time-sensitive plans. A quick glance at a live GMT clock will settle any confusion, and once you know whether the UK is on GMT or BST, you know exactly what time it is in Reykjavik.