Timezone Converter
Pick a date, time, and source timezone to instantly see the equivalent local time in 29 major timezones worldwide, including UTC offset for each. No external API — uses the browser's built-in Intl.DateTimeFormat.
Convert one wall-clock date and time from a selected source timezone into 29 configured IANA timezones, with each destination showing its local time and UTC offset.
How to convert time across timezones
- Enter a local date and time in the source timezone.
- Choose the source timezone from the configured list.
- Review the converted time and UTC offset for all 29 destinations.
- Use Now to reset the input to the current local date and time.
DST and timezone handling
The converter uses Intl.DateTimeFormat with IANA timezone names and iteratively resolves the entered wall time to an actual instant. This allows offsets to change automatically with daylight-saving rules supported by the browser.
If the entered local wall time does not exist because of a DST spring-forward gap, the parser rejects it instead of silently shifting it. The configured list is fixed to 29 zones rather than every IANA timezone.
Privacy and limitations
Timezone conversion is performed locally with your browser Intl timezone database, and this application does not send the entered date or timezone to an external server. Historical and future timezone results depend on the timezone data bundled with the user’s browser and operating environment.
Timezone Converter FAQ
How many timezones are included?
The current interface lists 29 configured IANA timezones.
Does it account for daylight saving time?
Yes, when the browser timezone database supports the relevant DST rules for the selected date.
What happens to a nonexistent DST time?
The tool rejects wall times that do not exist during a spring-forward gap.
Does it show UTC offsets?
Yes. Each zone displays an offset such as UTC+09:00 or UTC-04:00 for the chosen instant.
Can I add any IANA timezone manually?
No. This interface converts only among the zones included in its fixed list.