How this calculator works
Pick a date, time, and a 'from' and 'to' time zone from a curated list of 25 major zones, and this calculator converts between them using each zone's fixed standard-time offset from UTC. A table also shows what that exact moment looks like in every listed zone at once, along with the calendar-day shift and the UTC equivalent.
Every offset here is a STANDARD-TIME offset — the one used during the part of the year a zone is not observing daylight saving time. This calculator does not simulate daylight saving time at all: it is not a real per-date DST calculation, and faking one with a rough rule would silently produce wrong answers on the wrong dates. If you need a result for a zone during its DST period, add one hour to zones that observe it.
How the conversion works
UTC instant = entered local time − source zone's standard UTC offsetConverted time = UTC instant + target zone's standard UTC offsetOffsets are fixed, whole or half-hour standard-time values (for example, India Standard Time is a fixed UTC+5:30 year-round; it does not observe daylight saving time at all, unlike many zones in this list).
Worked example: US Eastern to Japan
- 10:00 PM (22:00) on March 10, 2024, US Eastern Standard Time (UTC-5).
- Convert to UTC: 22:00 + 5 hours = 03:00 UTC, now on March 11.
- Convert to Japan Standard Time (UTC+9): 03:00 + 9 hours = 12:00 (noon) on March 11.
- Result: 12:00 PM, March 11 in Japan — a 14-hour difference, and one calendar day later than the US Eastern date entered.
Frequently asked questions
Does this calculator apply daylight saving time?
No — it always uses each zone's standard-time offset, year-round. For a zone that observes daylight saving time, the real local clock will read one hour later than this result during roughly half the year (spring through fall in the Northern Hemisphere, fall through spring in the Southern Hemisphere). If you know the date falls within a zone's DST period, add one hour to that zone's result.
Why not just implement real daylight saving time rules?
DST start and end dates differ by country, have changed historically, and some regions don't observe it at all — implementing this correctly requires full time-zone-database (IANA tz) rules, not a handful of fixed offsets. Rather than approximate that and risk quietly wrong answers, this calculator states its standard-time-only limitation plainly.
Which zones in this list actually vary by DST in real life?
Most of Europe (CET, EET), most of the US and Canada (PST, MST, CST, EST, AST), Australia's eastern states (AEST), and New Zealand (NZST) typically observe daylight saving time for part of the year. Zones like UTC, India (IST), China (CST), Japan (JST), Hawaii (HST) and most equatorial zones (GST, EAT, WAT, PKT, BDT, ICT) do not observe DST at all, so their standard offset applies year-round.
Why do some zones have a 30- or 45-minute offset instead of a whole hour?
Some countries chose an offset that splits the difference between neighboring whole-hour zones — India Standard Time (UTC+5:30) and Australian Central Standard Time (UTC+9:30) are common examples used in this calculator's list.
Why does the same clock time sometimes land on a different calendar date?
Because time zones are offsets from a single UTC instant, converting from a zone far ahead to one far behind (or vice versa) can push the local calendar date forward or back a day, even if the hour and minute look similar. This calculator's 'calendar day change' result states exactly that shift for the conversion you entered.