Thailand Time Converter: ICT to UTC & US Time Zones

Why the date flips — and why July differs from January

Subtract 7 hours from Bangkok time and you get UTC: noon ICT is always 05:00 UTC, in January and in July alike, because Thailand never moves its clocks. The US side is where the shift happens. In January, New York is on Eastern Standard Time, UTC−5, so 05:00 UTC is midnight Eastern on the same day; Chicago, Denver, Los Angeles, and Honolulu are still on the previous day, at 11:00 PM, 10:00 PM, 9:00 PM, and 7:00 PM respectively. In July, New York is on Eastern Daylight Time, UTC−4, so the same 05:00 UTC is 1:00 AM Eastern, Chicago is at midnight on the same day, and Denver, Los Angeles, and Honolulu are still on the previous day at 11:00 PM, 10:00 PM, and 7:00 PM. The practical rule is simple and worth memorising: a Bangkok morning is the previous US evening, and a Bangkok evening is the same US morning — so when you book across the two, check the date first and the hour second.

Calling Bangkok at business hours

Bangkok business hours run roughly 9:00 AM to 6:00 PM ICT, which is 02:00 to 11:00 UTC. That window is 9:00 PM to 6:00 AM Eastern in January and 10:00 PM to 7:00 AM Eastern in July, so there is no comfortable overlap with a US 9-to-5: the realistic slots are a US evening call catching the start of the Bangkok day, or a very early US morning call catching its end. For the western US the window is three hours earlier still, and Hawaii, which never observes daylight saving, sits a fixed 17 hours behind Bangkok all year. If a meeting must fall inside both working days, the least-bad compromise is usually 8:00 or 9:00 PM Eastern, which is 8:00 or 9:00 AM the next day in Bangkok — book it the Bangkok way round, and put both dates in the invitation.

Output · formula · meaning

Who uses this

• The Bangkok business caller: books a 9:00 AM Bangkok start as 9:00 PM Eastern the night before, with both dates written in the invite.
• The Thailand traveller: checks a noon Bangkok flight connection and learns it is still the previous evening back home, so family pickups are planned for the right day.
• The remote team lead: compares January and July conversions and discovers the US meeting time shifts by an hour when US clocks change, even though Bangkok never moves.
• The Hawaii-based relative: sees a fixed 17-hour gap all year, because neither Thailand nor Hawaii observes daylight saving.

Accuracy & limitations

Conversions are computed from the UTC instant (Bangkok time minus 7 hours) and rendered with the browser's built-in time-zone data, so they follow the US daylight-saving rules in force on the chosen date rather than a fixed offset table. That also means results depend on the visitor's browser being up to date: if a government changes its rules after the browser's data was published, the conversion could be off until the browser updates. Thailand has a single time zone, so Bangkok, Chiang Mai, Phuket, and every other Thai city share exactly the same time. This tool converts clock times only; it does not account for flight durations, layovers, or the date line beyond the local-date rendering shown.