Runs in your browser
Time Zone Converter
Convert a date and time from one time zone to another using the browser's real IANA time zone data — not a fixed UTC-offset table — so daylight-saving transitions are handled correctly for whatever date you convert.
ReadyDeveloper UtilitiesFree · No account required
Related tools
Features
- Real IANA time zone data via the browser’s Intl API — not a fixed offset table
- Correct daylight-saving handling for the specific date you convert
- Swap source and destination with one click
- “Use current date/time” shortcut
- Shows each zone’s abbreviation (e.g. EDT, GMT) for the converted instant
How to use
- Pick the source time zone and the date/time in that zone.
- Pick the destination time zone.
- The converted date and time appear automatically.
- Use Swap to convert in the other direction.
Example
10:30 AM, Sep 14 in New York → 3:30 PM, Sep 14 in London
FAQ
- Does this handle daylight saving time correctly?
- Yes. It uses your browser's real IANA time zone database (the same data behind Intl.DateTimeFormat) rather than a fixed UTC-offset table, so the correct offset for the specific date you convert — before or after a DST transition — is used automatically.
- What happens with a time that doesn't exist, like during a spring-forward transition?
- Twice a year, clocks in DST-observing regions skip an hour (spring forward) or repeat one (fall back), which makes some local times either nonexistent or ambiguous. This tool resolves those cases using the offset in effect at the nearest valid instant — the same practical approach most time zone tools take without asking you to disambiguate manually.
- Is my data sent anywhere?
- No — the conversion is computed entirely in your browser using the Web platform's Intl API. No external time zone API is called.