Convert GMT (Greenwich Mean Time) to ICT (Indochina Time)

Best time to schedule a meeting

Standard 9–5 working hours overlap for 1 hour: 9:00 AM–10:00 AM GMT (4:00 PM–5:00 PM ICT). Schedule meetings inside that window.

GMT to ICT conversion table

About GMT

Greenwich Mean Time (GMT) is UTC+0. It is used in the UK and Ireland in winter, Portugal, Iceland and much of West Africa.

The trap with GMT is that the United Kingdom is not on it for most of the year. From late March to late October the UK runs BST, UTC+1, so a meeting agreed "10am GMT" with a London colleague in July is an hour out unless both parties meant the abbreviation literally. Broadcasters and airlines avoid the ambiguity by saying UTC. GMT itself is fixed at UTC+0 and does not shift; it is the UK's clocks that move away from it and back.

About ICT

Indochina Time (ICT) is UTC+7. It is used in Bangkok, Hanoi, Ho Chi Minh City and Jakarta.

Indochina Time is UTC+7, covering Thailand, Vietnam, Cambodia and Laos, with no daylight saving in any of them. Bangkok and Hanoi keep the same clock, which makes the region unusually simple to schedule across — the complication is only ever with the countries around it, since Myanmar is at UTC+6:30 and Malaysia at UTC+8.

Does this gap change with the seasons?

This gap is seasonal. The abbreviations themselves are fixed offsets, but the region on GMT switches to BST (UTC+1) from late March to late October. So the 7-hour figure on this page is correct for the part of the year when both places are actually on these abbreviations, and changes by an hour outside it.

ICT does not shift, so the whole change comes from one side. A recurring meeting fixed in ICT will appear to move by an hour for everyone on the other side, twice a year, without anyone changing anything.

This is the reason scheduling systems store an IANA zone such as Region/City rather than an offset or an abbreviation: the zone knows its own rules and the offset does not.

Frequently asked questions