Time Zone Converter

How Time Zone Converter Works

This tool converts a specific date and time from one time zone to another, using your browser's own time zone database so it automatically accounts for each region's current daylight saving time rules -- no manual offset lookup required.

Formula & Method

The calculator reads the wall-clock time you enter as if it were local to your chosen "from" zone, resolves that to a single absolute moment in time (handling daylight saving transitions by checking the zone's offset both before and after an initial estimate), and then re-displays that same absolute moment using your "to" zone's local calendar and clock. The time difference shown is simply the destination zone's UTC offset minus the origin zone's UTC offset at that specific moment -- which is why the difference between two zones can change across a daylight saving transition.

Worked Example

Converting 9:00 AM on August 3, 2026 in New York (America/New_York, on Eastern Daylight Time, UTC−4) to India Standard Time (Asia/Kolkata, UTC+5:30) gives 6:30 PM the same day. The time difference is +9h 30m, since Kolkata is 9 hours and 30 minutes ahead of New York at that moment, and both times fall on the same calendar day.

Frequently Asked Questions

Does this account for daylight saving time automatically?

Yes -- the tool reads each zone's actual daylight saving rules for the date you've chosen, so a conversion made in summer and one made in winter for the same two zones can show a different time difference if one or both zones observe daylight saving time.

Why does the destination date sometimes show as the next day or previous day?

Time zones can be far enough apart that converting a time near midnight in one zone lands on a different calendar date in the other. The "Day" stat tells you whether the converted time falls on the same day, the next day, or the previous day relative to the original date you entered.

What time zone list does this use?

It uses your browser's built-in IANA time zone database (via Intl.supportedValuesOf('timeZone')) when available, which covers essentially every named time zone in the world; on older browsers without that feature, it falls back to a shorter list of commonly used zones.