Time Zone Converter
Convert any date and time between time zones.
Overview
The Time Zone Converter translates any date and time between IANA zones. Enter a moment in Europe/London, choose America/Los_Angeles as the target, and the tool returns the equivalent local clock reading along with both UTC offsets — useful when scheduling a call across continents or confirming when a published "10:00 GMT" deadline actually hits in your zone.
Useful for global engineering teams scheduling syncs, support agents quoting maintenance windows to international customers, travellers checking when their flight lands in local time, and developers debugging "the email said 5pm Pacific, but my calendar imported 8pm Eastern" mishaps.
How it works
The conversion uses the IANA tz database (Olson database), the authoritative source for civil time rules worldwide and the data set behind TimeZoneInfo in .NET. Each zone carries its full history of DST transitions, so the offset applied is the one in effect on the exact date you enter — not the zone's nominal "standard time" offset.
For the ambiguous fall-back hour (where the same local time happens twice), the converter assumes the first occurrence (still in DST). For the missing spring-forward hour (where a local time does not exist), the input is shifted forward to the next valid instant. Both behaviours match the .NET TimeZoneInfo.ConvertTime defaults and the W3C HTML datetime-local semantics.
Examples
2026-05-18 14:00 Europe/London (+01:00 BST)
→ 2026-05-18 06:00 America/Los_Angeles (−07:00 PDT)
2026-12-25 09:00 Asia/Tokyo (+09:00)
→ 2026-12-25 00:00 UTC
→ 2026-12-24 19:00 America/New_York (−05:00 EST)
2026-10-25 01:30 Europe/London (ambiguous, falls back at 02:00 → 01:00)
→ Reported as the +01:00 BST instant by default
FAQ
What is the difference between Europe/London and GMT?
Europe/London follows British civil time including BST (Greenwich Mean Time + 1 hour) from late March to late October. GMT is a fixed +00:00 offset year-round and does not switch.
Why use IANA zone names instead of UTC offsets?
Offsets do not capture DST rules. Saying "I will call you at 14:00 Europe/Paris" is unambiguous all year; saying "14:00 +01:00" is wrong half the year for Paris.
What happens during a DST transition?
For the fall-back ambiguous hour, the first (DST) occurrence is used. For the spring-forward missing hour, the input rolls forward to the next valid local time. Both follow the .NET ConvertTime default.
Why does my Indian colleague have a +05:30 offset?
India Standard Time is fixed at UTC+05:30 — one of several half-hour offsets used around the world (Iran +03:30, Newfoundland −03:30, Nepal +05:45).
Can I convert a recurring meeting time?
This tool converts one instant. For recurring meetings spanning a DST transition, run the conversion for each occurrence — the offsets will shift across the boundary.