Convert a Time Between Two Zones

This page converts a specific time. If you only want to know what an abbreviation means or what a given offset reads as elsewhere, the UTC offsets and time zone abbreviations page is the reference.

Time zones divide the world into regions that observe the same standard time. The system is based on Coordinated Universal Time (UTC), with each zone offset by a certain number of hours (and sometimes half-hours) from UTC. For example, New York operates on UTC-5 during standard time, while Tokyo is UTC+9, making Tokyo 14 hours ahead of New York in winter.

This calculator lets you convert a time from one zone to another by selecting the UTC offsets for both locations and entering your local time. The conversion formula is straightforward: take the source time, subtract the source UTC offset, then add the destination UTC offset. If the result goes past midnight (above 24 or below 0), the calculator adjusts the time and indicates a day change.

The map is drawn as 24 hour-wide bands, but the world does not actually run on 24 zones. Once you count the countries that sit on a half hour or a quarter hour, and the ones that have quietly redrawn their borders, there are around 38 distinct offsets in use at any moment: UTC+5:30 in India, UTC+5:45 in Nepal, UTC+9:30 in Central Australia, UTC+12:45 in the Chatham Islands. China is the opposite extreme, running its entire 5,000 km width on a single offset, so the sun comes up in Kashgar at what the clock insists is mid-morning.

The gap between the neat diagram and the messy reality is why converting in your head goes wrong. Convert through UTC instead, which is what this calculator does: strip the source offset off to reach UTC, then add the destination offset on.

Daylight saving time is the other complication, and it is the one that catches people out. Many regions shift forward an hour in summer, but not all of them, and those that do change on different dates. For roughly three weeks each March and October, Europe and the United States are an hour closer together or further apart than usual, because they switch on different weekends. This calculator uses standard (winter) offsets, so add an hour to any location currently on summer time before you select it.

If a meeting matters, confirm the DST status of both ends rather than assuming. The most common failure is not a wrong conversion; it is a correct conversion done against an offset that changed last Sunday.