Convert Time Between Timezones

All IANA timezones supported by your browser – typically 400+ on Chrome, Firefox, Edge, and modern Safari (which uses the ICU timezone database). The list comes from Intl.supportedValuesOf('timeZone'). On older browsers without that API, the tool falls back to a curated list of ~34 major timezones. Either way, every major and minor zone you’d want for scheduling is covered.

That sibling tool maps each country to one IANA timezone (the capital’s). This one exposes raw IANA timezones directly – pick America/Los_Angeles instead of just “USA” if you specifically need Pacific Time vs Eastern. Use this for precise sub-country control and small islands; use the countries tool for casual country-to-country coordination.

Yes – on first load. The source defaults to Intl.DateTimeFormat().resolvedOptions().timeZone, which is your browser’s reported timezone (typically synced to your OS). The source info row shows the IANA identifier and current UTC offset so you can verify it picked the right one. You can override by selecting any other zone from the drop-down.

Yes – via the browser’s IANA timezone database accessed through Intl.DateTimeFormat with timeZoneName: 'longOffset'. Each conversion looks up the offset for the specific date you’ve chosen, so spring-forward and fall-back transitions are respected. The DST badge per target tells you when daylight saving is currently in effect for that zone.

India is UTC+05:30 (not +05). Iran is UTC+03:30. Nepal is UTC+05:45. Newfoundland is UTC-03:30. Several Pacific islands have 45-minute offsets. Rounding these to whole hours loses real time. This tool calculates and displays everything in minutes precision – Nepal shows +5h 45m not +6h. Many calculator tools silently round; this one preserves the actual offset.

Shows when the converted wall-clock falls on a different calendar day from the source. Converting 23:00 NYC on June 2 to Tokyo gives 12:00 on June 3 – the badge shows +1 day. Convert 02:00 Tokyo back to NYC and you get 13:00 the previous day – -1 day. Especially important when scheduling meetings; the badge prevents day-bookkeeping mistakes.

Yes – and you should. Many cross-Atlantic meetings get scheduled in March or November when one or both regions switch DST. The offset between New York and London is usually 5 hours, but during the 1-week overlap when London has fallen back but NYC hasn’t, it’s 4 hours. Pick the future meeting date and the tool applies the offsets actually in effect, no surprises.

UTC-12 (Baker Island, US) to UTC+14 (Line Islands, Kiribati). That’s a 26-hour range – meaning if it’s noon in Kiribati, it’s 10am yesterday in Baker Island. The day-offset badge flags this when it happens. All IANA zones in those ranges work.

No. All timezone math runs in your browser using Intl.DateTimeFormat against the browser’s local IANA database. Open DevTools → Network and confirm zero requests fire – even when you Convert or Download. Safe for confidential meeting times, travel plans, or any time data you’d rather not log to a third-party converter.

Yes. Total bundle is about 22 KB, and the IANA timezone database is part of the browser (shipped with the OS or browser binary), not a remote API. Load once, disconnect, keep converting. Useful for travel planning on planes or rapid time-zone math in airgapped dev environments.