Time Zone Converter

Convert a date and time from one time zone to another — daylight saving time handled automatically using your browser's built-in time zone database. Perfect for scheduling calls across offices, catching global launches and booking flights.

How to use this calculator

Enter the date and time of your event or meeting.
Choose which zone that time is in, and which zone you want it converted to.
Press Convert — DST rules for that specific date are applied automatically.
The UTC row gives you a universal reference for calendar invites.

Formula used

Target time = Source time + (Target UTC offset − Source UTC offset)

Offsets change with daylight saving, so the correct conversion depends on the date, not just the cities. This tool uses the IANA time zone database built into your browser, which tracks every zone's DST rules.

Example calculation

Worked example

A call at 15:00 in India (IST, UTC+5:30) in July converts to 05:30 in New York (EDT, UTC−4 during summer) — a 9.5-hour difference.

The same 15:00 IST call in January lands at 04:30 New York time, because New York shifts to EST (UTC−5) in winter while India never changes.

Why time zone math goes wrong

Two things break naive time zone conversion: daylight saving and half-hour offsets. DST means the gap between two cities changes twice a year — London and New York are usually 5 hours apart but briefly 4 during the weeks their clocks change on different dates. And several major zones (India +5:30, Iran +3:30, Nepal +5:45) don't sit on whole hours at all.

The reliable method is converting through UTC using the actual rules for the specific date — exactly what this tool does. For recurring international meetings, always anchor the invitation in one named zone or UTC.

Why use this calculator?

Schedule international calls without the classic off-by-one-hour DST mistake.
Handles half-hour zones like India's +5:30 that mental math mangles.
Get the UTC equivalent for unambiguous calendar invites.

Frequently asked questions

Does this handle daylight saving time?

Yes — automatically, per date. The converter uses your browser's IANA time zone database, so a July conversion uses summer offsets and a January conversion uses winter ones, including the awkward weeks when only one side has switched.

What is the time difference between India and the USA?

India (IST, UTC+5:30) is 9.5 hours ahead of New York in summer (EDT) and 10.5 in winter (EST); 12.5–13.5 hours ahead of Los Angeles. India doesn't observe DST, so the change comes entirely from the US side.

Why isn't my city listed?

Cities in the same zone share rules — pick any listed city in your zone (e.g. Paris users pick Berlin, Toronto users pick New York). More zones are on the roadmap.