Convert times between any timezones instantly. See current time in multiple cities worldwide. Free online timezone converter.
This free online timezone converter lets you instantly convert any date and time between any two timezones in the world. Select a source timezone and date, then add as many target timezones as you need. Results update live as you type.
All conversions are performed locally in your browser using the JavaScript Intl.DateTimeFormat API
with IANA timezone data - entered time values are not uploaded for processing. Daylight Saving Time (DST) transitions are handled automatically.
Enter your date and time in the input field above, select your source timezone (or click "Use Now" to use the current time), and the tool instantly converts it to all target timezones listed in the results panel. Add more timezones with the "+ Add Timezone" button, or remove any with the X button. Each result shows the converted time along with its UTC offset. All conversions use the JavaScript Intl.DateTimeFormat API with full IANA timezone database, so Daylight Saving Time transitions are handled automatically.
UTC (Coordinated Universal Time) is the primary global time standard - all other timezones are defined as offsets from UTC. GMT (Greenwich Mean Time) is historically the same as UTC, but GMT is a timezone that observes no DST (it stays at UTC+0 year-round), while UTC is a time standard not a timezone. EST (Eastern Standard Time) is UTC-5, but New York switches to EDT (UTC-4) in summer. IST refers to India Standard Time (UTC+5:30) but also Irish Standard Time (UTC+1) and Israel Standard Time (UTC+2) - this is why IANA timezone names like Asia/Kolkata are unambiguous.
Daylight Saving Time (DST) is the practice of advancing clocks by one hour in spring and reverting in autumn to extend evening daylight. The US and Canada observe DST (clocks "spring forward" on the second Sunday of March, "fall back" on the first Sunday of November). Most of Europe observes it on the last Sunday of March and October. Countries near the equator and many in Asia (India, Japan, China) do not observe DST. The timezone converter above automatically accounts for DST transitions - if you convert a summer date, New York shows UTC-4, and a winter date shows UTC-5.
The golden rule is: store timestamps in UTC, display in local time. In JavaScript, Date objects are always UTC internally - use Date.now() or new Date().toISOString() for UTC storage. Convert to local display using Intl.DateTimeFormat with a timeZone option. In databases, use TIMESTAMP WITH TIME ZONE (PostgreSQL) or DATETIME (MySQL) with UTC as the server timezone. Never store local times directly - they become ambiguous when DST changes occur or users are in different timezones.
IANA timezone names (from the IANA Time Zone Database, also called the Olson database) are the official identifiers for every timezone, in the format Continent/City - for example America/New_York, Europe/London, Asia/Tokyo. They are used in JavaScript's Intl API, in operating systems, in databases, and in most programming languages. The database is updated several times per year to reflect timezone law changes. This converter includes 60 major IANA timezone zones covering every populated region of the world.