The reliable timezone converter for developers and teams
Converting a time from one time zone to another sounds trivial until daylight saving, half-hour offsets, and historical rule changes get involved. A meeting set for "3 PM Eastern" lands at a different UTC instant in summer than in winter, and India's IST sits at an awkward +5:30 that breaks naive mental math. This timezone converter removes the guesswork: enter the time once, choose its source zone, and read the exact equivalent everywhere else — with daylight saving applied automatically for the specific date you pick.
Why timezone math is hard
Every timezone is defined as an offset from UTC (Coordinated Universal Time), but those offsets are not constant. Most of North America and Europe shift their clocks twice a year for daylight saving, and the exact switch dates differ by region and have changed repeatedly through history. Some places, like Arizona and most of India, never observe DST at all. A handful use 30- or 45-minute offsets. Hard-coding "+5 hours" or "subtract 8" will eventually produce a wrong answer. The only robust approach is to use a maintained timezone database, which is exactly what this tool does.
Built on the IANA timezone database
This converter uses your browser's native Intl.DateTimeFormat API, which is backed by the IANA timezone database (also called the tz or zoneinfo database) — the same authoritative dataset used by Linux, macOS, Java, and most programming languages. That means every conversion respects the real DST transition dates and offset history for the region, for past, present and future dates. You are seeing the same result your production servers would compute, which is why this is a developer-grade tool rather than a rough approximation.
Common conversions
- EST/EDT ↔ IST — New York to India is +9:30 or +10:30 depending on US daylight saving; the converter picks the right one for your date.
- PST/PDT ↔ IST — Los Angeles to India spans +12:30 or +13:30, a frequent source of scheduling errors.
- UTC ↔ local — turn a log timestamp recorded in UTC into your wall-clock time, or vice-versa.
- London ↔ Singapore ↔ Sydney — coordinate a call across three continents at a glance.
Scheduling meetings across continents
Add every participant's timezone as a target and you instantly have a mini world clock anchored to your proposed start time. Nudge the source time and watch all the targets update together until you find a slot that is reasonable for everyone. Because the tool runs entirely client-side, there is no signup and nothing you enter is sent anywhere — it is just as suitable for internal release windows as for personal scheduling.
From wall-clock to absolute time
Under the hood, the converter treats your input as a wall-clock time in the chosen source zone, resolves it to a single absolute UTC instant, and then formats that instant for each target zone. This two-step model is what makes it correct around DST boundaries, where the same wall-clock time can be ambiguous. If you also need the raw integer behind a moment, head to the epoch converter; and if you are scheduling a recurring job rather than a one-off, the cron expression generator will turn your intended schedule into a crontab line.