Convert ICT (Indochina Time) to HST (Hawaii Standard Time)

Best time to schedule a meeting

Standard 9–5 working hours do not overlap at all between ICT and HST. Someone has to take an early or late call — or use asynchronous communication instead.

ICT to HST conversion table

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.

About HST

Hawaii Standard Time (HST) is UTC−10. It is used in Hawaii, which does not observe daylight saving at all.

Hawaii–Aleutian Standard Time is UTC−10 and Hawaii does not observe daylight saving. That makes it the North American zone whose relationship to everywhere else changes twice a year without it doing anything: Hawaii is two hours behind Los Angeles in winter and three in summer. It is also far enough west that the working day barely overlaps with the US east coast at all.

Does this gap change with the seasons?

Neither ICT nor HST shifts with the seasons, so this 17-hour difference holds all year. That is unusual enough to be worth relying on: most cross-continental gaps move twice a year.

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