Time Zone Calculator

Why this doesn't just add or subtract a fixed number of hours

Time zone offsets aren't constant year-round — daylight saving time shifts many zones by an hour for part of the year, and not every country observes it the same way or on the same dates. This tool uses your browser's built-in time zone database (via Intl.DateTimeFormat) rather than a hardcoded offset, so daylight saving is handled automatically for the date you pick.

A mistake worth avoiding

Scheduling a recurring meeting "at the same UTC offset" every week can quietly drift by an hour when one region's daylight saving starts or ends on a different date than the other's — this is why global teams occasionally show up an hour off. Recalculating for the actual date, not just once, avoids that.