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Date & Time

Time Zone Converter

Convert times between any IANA time zones with full daylight-saving awareness, plus a side-by-side world clock for scheduling calls.

Extra zones to compare
ZoneOffsetLocal date & time
America/New_YorkUTC−04:00Tue 20 Oct, 09:15
Europe/Madrid (source)UTC+02:00Tue 20 Oct, 15:15
Asia/TokyoUTC+09:00Tue 20 Oct, 22:15

Uses the browser’s built-in IANA zone database with full DST rules — conversions run offline.

Half-Hour Zones and Other Irregularities

Not every zone runs on whole hours: India is UTC+5:30, Nepal UTC+5:45, and parts of Australia UTC+9:30. Offsets also shift with DST on different dates per hemisphere — Europe and the US change weeks apart, so the gap between Madrid and New York is 6 hours most of the year and 5 or 7 for a couple of weeks each spring and autumn.

The reliable workflow: convert the exact moment (this tool does), then write the local time with its zone (14:00 CET) rather than a raw offset that goes stale twice a year.

How the Dates Are Calculated

  1. Enter a date and time, choose the source zone, and pick one or more target zones.
  2. All zones use the browser’s IANA database (e.g. Europe/Madrid, America/New_York) with correct DST transitions.
  3. The world clock table shows the same moment across common zones, sorted by offset.
  4. A visual alignment bar helps find overlap windows for international meetings.
Formula & Technical Standard
Zone offsets come from Intl.DateTimeFormat with timeZoneName offsets; DST transitions resolved per IANA rules for the specific date.

Worked Example

Schedule a global call
Input: 15:00 Europe/Madrid → America/New_York, Asia/Tokyo
Output: 09:00 New York · 22:00 Tokyo
Seeing all zones at once makes it obvious which meeting slot avoids midnight for any participant.
DST transition check
Input: 2026-03-29 02:30 Europe/Madrid
Output: Converted correctly across the spring-forward gap
Times inside a DST gap do not exist locally; the tool resolves them to the correct UTC instant.

Common Questions

Why use zone names instead of fixed offsets?

Fixed offsets (UTC+1) ignore daylight saving. Zone names like Europe/Madrid carry the full rule set, so conversions stay correct all year.

Does it need internet access?

No. The IANA database ships inside your browser and the conversion is fully local.

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