Time Zone Converter
Convert a date and time between any two world time zones. Daylight saving is applied for the actual date you enter, not a fixed offset, and you are warned when the conversion lands on a different calendar day — the mistake that gets people onto calls a day early.
Convert between time zones
Why a fixed offset is not good enough
"New York is five hours behind London" is true for part of the year and wrong for the rest. The two places change clocks on different dates, so for a couple of weeks each spring and autumn the gap is four hours or six, not five.
This converter asks for the date as well as the time and applies the rules in force on that date, using the time zone database built into your browser. A meeting arranged during one of those gap weeks using a remembered offset is the classic way to turn up an hour out.
How to use this calculator
- Enter the date and the time, in 24-hour form.
- Choose the zone that time is in, and the zone you want it in. Your own zone is filled in as the source.
- Press Calculate. You get the converted time, both offsets, and a warning if the day changes.
The day change is the real trap
9am Wednesday in New York is 10pm Wednesday in Tokyo, but 9pm Wednesday in New York is 10am Thursday in Tokyo. The time is easy to convert in your head; the date change is what gets missed, and it is why invitations land on the wrong day.
The result flags it explicitly whenever the converted time falls on a different calendar date.
Planning a call across zones
Convert the time into each participant's zone one at a time and check the local hour is civil in all of them. Watch for the Asia-Pacific day change, and for half-hour and forty-five-minute offsets — India is UTC+5:30, Nepal UTC+5:45, and parts of Australia run on half hours. The converter handles all of those; a mental calculation usually does not.
Frequently Asked Questions
How do I convert time between different time zones?
Enter the date and time, pick the zone it is in and the zone you want, and press Calculate. The date matters as much as the time, because daylight saving changes the offset at different points in the year in different places.
Does this handle daylight saving time?
Yes, and for the specific date you enter rather than a fixed offset. It uses the IANA time zone database built into your browser, so the rules are the real ones in force on that date.
Why does the converted time land on a different day?
Because the offset between the zones is larger than the time left in the day. 9pm Wednesday in New York is 10am Thursday in Tokyo. The result says so explicitly whenever the calendar day changes.
What is the best time for an international meeting?
Convert the proposed time into each person's zone and check the local hour is reasonable for all of them. Pay attention to the day change for Asia-Pacific participants, and to half-hour offsets such as India at UTC+5:30.
Why do some zones have offsets that are not whole hours?
Because time zones are political rather than geometric. India is UTC+5:30, Nepal UTC+5:45, and several Australian zones use half hours. The converter handles them; arithmetic in your head usually does not.