Timezone london

How it works

Timezone london is the zone Europe/London. In winter the civil label is GMT, offset UTC+0. In summer the civil label is BST, offset UTC+1. The United Kingdom currently changes on the last Sunday of March (forward) and the last Sunday of October (back). In 2026 those Sundays are 29 March and 25 October.

A pair is two clocks at one instant. You do not add “London” to “New York” as if they were numbers. You read each side’s offset that day, then subtract. London GMT to New York EST (UTC−5) is five hours: noon in London is 7 a.m. in New York. London BST to New York EDT (UTC−4) is still five hours: noon in London is 7 a.m. in New York. The usual pair is five hours. The exceptions are the weeks when only one side has changed.

Write a city or an IANA name on the invite: Europe/London, America/New_York, Europe/Paris. Letters such as GMT and EST are nicknames. They are enough when both people share the same map. They fail when “London time” is used in June and someone still thinks GMT.

London and New York, the long pair

The United States currently springs forward on the second Sunday in March and falls back on the first Sunday in November. In 2026 that is 8 March and 1 November. The UK moves later in spring and earlier in autumn. The pair therefore has two short seasons when the gap is four hours, not five:

After the U.S. spring change and before the UK spring change: New York on EDT (UTC−4), London still on GMT (UTC+0). Gap: four hours. After the UK autumn change and before the U.S. autumn change: London on GMT (UTC+0), New York still on EDT (UTC−4). Gap: four hours.

The rest of the year, when both are on standard labels or both are on summer labels: five hours, London ahead. Los Angeles is a longer pair. Pacific Standard Time is UTC−8; Pacific Daylight Time is UTC−7. Against GMT that is eight hours; against BST that is eight hours as well, except in those same mismatch weeks, when it is seven. A 9 a.m. London start is then 1 a.m. or 2 a.m. on the Pacific coast, which is why a “morning” meeting is not morning on both desks.

Do not convert from “England time” or “Britain time.” Northern Ireland uses the same civil zone as London. Ireland in the Republic uses Dublin’s own zone, which usually matches London’s offset but is not the same legal clock. A city name is safer than a country name.

London is not five hours from New York. London is five hours from Eastern time when both labels are in the same season. The river did not move. The letters did.

London and Paris, the short pair

Paris uses Central European Time (UTC+1) in winter and Central European Summer Time (UTC+2) in summer. The European Union currently changes on the same last Sundays as the UK. The ordinary pair is one hour: Paris is ahead of London. Noon in London is 13:00 in Paris, in winter and in summer, while those rules hold.

That one-hour pair is easy to ignore, then miss. A train, a call, and a shop cutoff all live on the local clock. If you land at CDG and your phone is still on Europe/London, you are an hour behind the hall screens. Set the phone to the city you are in, then convert the other city from there.

Other close European pairs follow the same method: read both offsets, subtract, write both names. Do not assume a country that “feels nearby” shares BST. Spain is on Central European time, so Madrid sits with Paris, not with London, despite the longitude. The zone is a legal choice, not a meridian you can see from the plane.