Free Timezone Converter
Convert a date and time between any two timezones — daylight saving is handled automatically.
How timezone conversion actually works
Every timezone selector on this page uses names like America/New_York or Asia/Kolkata instead of abbreviations like "EST" or "IST" — and that's a deliberate, important choice. Abbreviations are ambiguous: "IST" alone could mean Indian Standard Time, Irish Standard Time, or Israel Standard Time, and "CST" is shared by Central Standard Time (US) and China Standard Time. City-based names come from the IANA Time Zone Database (sometimes called the "Olson" database), the same dataset built into every modern browser, which tracks each region's full history of offset and daylight-saving rule changes going back decades — not just its current offset.
That distinction matters because a timezone's offset from UTC isn't a fixed number — it changes twice a year in the roughly 70 countries that observe daylight saving time. This converter doesn't hardcode any offsets; it asks the browser "what was this zone's actual clock time for this specific date," which is why a January conversion and a July conversion between the same two zones can produce different offsets.
The "fall back" ambiguity
Once a year, DST-observing zones roll clocks back an hour, which means one local time — say, 1:30 AM — technically happens twice in the same night. Software has to pick one interpretation; this converter resolves it consistently by taking the UTC instant that the browser's timezone database returns for that wall-clock time, which corresponds to the first occurrence.
Frequently Asked Questions
Does this handle daylight saving time correctly?
Yes. The conversion looks up each timezone's actual UTC offset for the specific date you enter, so it automatically accounts for daylight saving transitions instead of using a fixed offset per zone.
What if the time I enter doesn't exist (a DST "spring forward" gap)?
Twice a year, clocks in DST-observing zones skip an hour (e.g., 2:00 AM becomes 3:00 AM) and that hour never occurs locally. If you enter a time in that gap, the converter resolves it to the nearest valid instant rather than failing — double-check results near known DST transition dates.
Why are some timezones offset by 30 or 45 minutes?
Not every timezone is a whole-hour offset from UTC — India (UTC+5:30) and Nepal (UTC+5:45) are common examples. The converter handles these correctly since it reads each zone's real offset rather than assuming whole hours.
Why does the list use names like "America/New_York" instead of "EST"?
Because abbreviations are ambiguous — several unrelated timezones around the world share the same three-letter abbreviation — while city-based IANA names uniquely identify one region's complete history of offset and DST rules, which is what makes accurate historical and future conversions possible at all.
Which timezone should I pick for "UTC"?
UTC is listed at the top of both dropdowns. It has no daylight saving shifts, which makes it the standard reference point for scheduling anything across multiple regions — server logs, international meetings, and API timestamps are conventionally stored in UTC for exactly that reason.
Is my data sent anywhere?
No. The conversion runs entirely in your browser using its built-in timezone database. Nothing is transmitted or stored.