Time Zone Converter
Convert any time between two time zones with automatic daylight-saving handling. Built for distributed teams and travel planning.
What this calculates
Time zones are messier than they look — daylight-saving rules, half-hour offsets, and historical changes mean naive math gets it wrong half the year. This converter uses your browser's built-in IANA time zone database so it always picks the right offset for the date you choose, including DST transitions like 'spring forward' weekends.
Formula & how it works
We use the IANA time zone database via the JavaScript Intl API. Convert: take the source date-time, interpret it in the source IANA zone (e.g., America/New_York), get the equivalent UTC instant, then format that instant in the target zone (e.g., Europe/London). Crucially this method handles DST automatically — converting 2026-03-08 10:00 New York to London gives 14:00 if it's still EST, or 15:00 once DST has started.
Worked example
9:00 AM in New York (America/New_York) on 2026-06-15 = 2:00 PM London (Europe/London) = 9:00 PM Tokyo (Asia/Tokyo) = 9:00 AM PDT in Los Angeles is actually 12:00 noon New York on the same date. Each conversion accounts for current DST: New York is 4 hours behind UTC in summer, 5 hours behind in winter.
Frequently asked questions
Does this handle daylight saving correctly?
Yes. The IANA database tracks DST rules per zone and per year. A meeting scheduled for 'Friday 3 PM London' lands at 10 AM New York in summer but 11 AM in winter — the converter gets this right because it operates on real calendar dates, not generic UTC offsets.
Why are some zones half-hours off?
Several regions sit on half-hour offsets — India (+5:30), Iran (+3:30), Newfoundland (−3:30) — and Nepal is even quirkier at +5:45. These reflect historical decisions to pick a noon-time roughly when the sun is highest. They're correctly handled here.
What about cities that don't appear in the list?
Most cities follow the same IANA zone as their capital or largest city. Search for the country in this dropdown to find the right zone. Time zones with multiple rules per country (e.g., USA, Russia, Australia) have several entries — pick the one closest to your city.
Is the converter accurate near a DST transition?
Yes — but be aware that 'ambiguous' times around the transition (e.g., 1:30 AM during the fall-back hour) have two valid UTC equivalents. We pick the earlier one by convention. Schedule meetings outside the 2 AM hour on transition weekends to avoid ambiguity.