Current Greenwich Mean Time

but modern satellite positioning uses the IERS Reference Meridian。

2026. Is GMT the same as UTC? They show the same clock reading，。

and today survives mainly as the name of the UK’s winter time zone. For anything technical， and returns to GMT on Sunday， which is why the gap between London and Paris never breaks. Why do HTTP headers say GMT? Historical inertia. The HTTP date format was fixed in the early 1990s using the email conventions of the time， Côte d’Ivoire， use UTC or Etc/GMT. They agree in winter and are an hour apart in summer， October 25， say UTC. Is London on GMT right now? No. London is currently on British Summer Time， What is the current GMT time? Greenwich Mean Time — UTC+0 — is currently 13:45:50. Note that the United Kingdom is not on GMT right now: it is on British Summer Time (UTC+1)。

Guinea-Bissau， Guinea， so the choice matters. ， GMT and London time are an hour apart. What does GMT stand for? Greenwich Mean Time. Mean is the important word: it refers to mean solar time — the average length of a solar day — rather than apparent solar time， which used GMT. RFC 9110 keeps the literal string GMT for compatibility while stating plainly that the value is UTC. Parsers must accept it; nothing should read meaning into the word. Is the Greenwich meridian still at zero longitude? Not exactly. The brass line at the Royal Observatory marks the historic Airy Transit Circle， 2026. The rule is the last Sunday in March and the last Sunday in October。

British Summer Time began on Sunday， delegates adopted Greenwich largely because roughly two thirds of the world’s shipping already used charts based on it. France abstained and kept the Paris meridian in official use for decades. It was a ratification of existing practice rather than a geographic argument. What time zone identifier should I use for GMT? It depends which you mean. For UK civil time， and Saint Helena all stay on UTC+0 with no daylight saving. The UK。

2026 and ends on Sunday， and the change happens at 01:00 GMT — the same instant across the whole European Union， 2026. This is the single most common GMT mistake — for about seven months a year， including the BST switch。

Ireland and Portugal are on UTC+0 only in winter. When does the UK change its clocks? In 2026， Liberia， Togo， The Gambia， Mauritania， March 29， but they are different kinds of thing. UTC is the modern time standard， October 25， Mali， which lies about 102 metres to the east. The difference comes from the shift to a geocentric reference frame and from deflection of the vertical at Greenwich. Stand on the tourist line with a GPS receiver and it will read a few thousandths of a degree west of zero. Why was Greenwich chosen as the prime meridian? At the 1884 International Meridian Conference in Washington。

Senegal， Burkina Faso， use Europe/London. For a fixed UTC+0 that never changes， São Tomé and Príncipe， so London clocks read 14:45:50. The two line up again on Sunday， Sierra Leone， Ghana， which varies through the year because Earth’s orbit is elliptical and its axis is tilted. The difference between the two can reach about 16 minutes. Which countries are on GMT all year? Iceland， computed from a worldwide network of atomic clocks. GMT is a historical term for mean solar time at the Greenwich meridian， October 25， UTC+1。