DocomintTime Zone Converter
Convert a date and time from one time zone to another, across 20 major cities.
Converts a wall-clock date and time from one IANA time zone to another — correctly accounting for each zone's current daylight-saving offset at that specific date, rather than assuming a fixed year-round UTC offset, which is what makes most naive timezone math wrong by an hour during part of the year.
Example: 2:30 PM on August 8, 2026 in New York (EDT, UTC−4 in August) converts to 3:30 AM the next day in Tokyo (UTC+9, no DST) — a 13-hour difference that would be different in winter, when New York shifts to EST (UTC−5).
How it works
- Enter a date and time, then choose the source and destination time zones
- Press Convert
- The converted date/time and the hour difference appear instantly, computed on your device
Frequently asked questions
Does this account for daylight saving time changes?
Yes — the conversion looks up each time zone's actual UTC offset at the specific date and time you entered, which automatically reflects whether that zone is in daylight saving time or standard time on that date, rather than assuming a fixed year-round offset.
Why isn't the time difference between zones always a round number of hours?
Most time zones do use whole-hour offsets from UTC, but a handful (India, Iran, parts of Australia) use 30- or 45-minute offsets — converting to or from one of those zones can produce a non-round difference like 9.5 or 5.5 hours.
Is my numbers uploaded anywhere?
No — Time Zone Converter runs entirely in your browser using JavaScript/WebAssembly. Your numbers is never sent to a server.