Current Time in Greenwich Mean Time (GMT)

Greenwich Mean Time (GMT) sits at UTC+00:00 — the zero-point from which every other time zone on Earth is measured. Its origin traces to the Royal Observatory in Greenwich, London, where the Prime Meridian was established in 1884 as the international reference for global navigation and timekeeping. That historical function has never been replaced: GMT remains the anchor for international financial settlement, aviation coordination, and broadcast scheduling worldwide. The London Stock Exchange opens at 08:00 GMT, and its trading window directly overlaps with both the closing hours of Asian markets and the opening of European bourses — a concentration of capital flow that no other time zone replicates.

GMT covers a geographically distinct set of territories in Western Europe and West Africa, with meaningful variation in whether they observe Daylight Saving Time.

• ✦Europe: The United Kingdom and Ireland observe GMT during standard time (winter), shifting to BST and Irish Standard Time respectively in summer. Portugal also uses GMT as its standard offset, advancing to Western European Summer Time (WEST, UTC+1) during DST. Iceland is the notable exception — it remains at UTC+0 permanently, observing neither DST nor any seasonal offset change.
• ✦Africa: A broad band of West African nations uses UTC+0 year-round with no DST: Ghana, Senegal, Ivory Coast, Mali, Mauritania, Guinea, Burkina Faso, and others. These countries maintain a fixed GMT offset regardless of the season, meaning they fall in line with GMT in winter but diverge by one hour from BST-observing UK and Ireland between March and October.

The United Kingdom and Ireland advance their clocks to UTC+1 — British Summer Time (BST) and Irish Standard Time (IST) respectively — beginning on the last Sunday in March and reverting to GMT on the last Sunday in October. In 2026, clocks spring forward on March 29 and fall back on October 25. Portugal follows the same schedule under Western European Summer Time (WEST).

Iceland, Ghana, Senegal, and all other West African GMT nations do not observe DST. From late March through late October each year, a practical one-hour gap opens between London and Accra — a detail that matters for anyone scheduling calls across those corridors during summer months.

Scheduling from the Americas: New York (EST, UTC-5) is 5 hours behind GMT in winter, narrowing to 4 hours during the DST transition period in spring. A 14:00–17:00 GMT window corresponds to 09:00–12:00 EST — the most productive overlap for US East Coast and London collaboration. For US Central (CST, UTC-6) and West Coast (PST, UTC-8) teams, morning GMT hours are inaccessible during standard business hours, making 16:00–17:00 GMT the only viable real-time window before London closes.

Scheduling from Asia: Tokyo (JST, UTC+9) is 9 hours ahead of GMT. London's 08:00–09:00 opening corresponds to 17:00–18:00 in Tokyo — a narrow but functional overlap at the boundary of each city's workday. Singapore and Hong Kong (UTC+8) offer a slightly wider window: GMT's 09:00–10:00 aligns with their 17:00–18:00. For India (IST, UTC+5:30), a 09:30–11:00 GMT morning maps cleanly to 15:00–16:30 IST, making that window the standard choice for GMT–India business calls.