Time Zone Converter
Convert a date and time between time zones and compare many places at once.
- Runs in your browser
- Nothing is uploaded
- Free, no sign-up
Green times fall between 9:00 and 18:00 local time. Zone names and daylight-saving rules come from your browser's copy of the IANA time zone database, so results follow the rules in force on the date you choose.
About this tool
Pick a date, a time and the zone it is in, and see what the clock reads in every other zone you care about, with the date, the UTC offset and whether it falls in working hours. Daylight-saving changes are applied for the date you choose.
How to use it
- Choose the date and time, and the zone it is in. The page starts with your own zone and the current time.
- Read the other zones in the table; add or remove zones to suit.
- Copy the list to paste it into a message or invite.
Use zone names, not abbreviations
Abbreviations are ambiguous and zone names are not. CST can mean US Central Standard Time, China Standard Time or Cuba Standard Time. IST is India, Israel or Ireland. BST is British Summer Time or Bangladesh Standard Time.
The IANA names, such as Asia/Karachi, America/Chicago and Europe/London, identify a place and carry its entire history of offset and daylight-saving rules, which is why this tool uses them. The short abbreviation is shown for reference only.
The two times that misbehave
When clocks go forward, an hour of local time never happens. When they go back, an hour happens twice. Both catch out naive conversion:
- New York, 10 March 2024, 02:30 does not exist: the clock jumped from 02:00 to 03:00. This tool says so and shows the first moment after the jump.
- New York, 3 November 2024, 01:30 happens twice, once in daylight time and once in standard time. The tool shows the first and tells you it is ambiguous.
If you are scheduling something, avoid the early hours of a changeover day in either direction.
The gap between two cities is not constant
Countries change their clocks on different dates. The United States moves on the second Sunday of March and the first Sunday of November. Most of Europe moves on the last Sunday of March and October.
So New York is five hours behind London for most of the year, and four hours behind for about three weeks in March and again for about a week in the autumn. A recurring meeting held at a fixed UTC time will drift by an hour for one side of it. Zones such as Pakistan, India, Japan, China and the UAE do not change at all, so their gap to a changing zone shifts twice a year.
Scheduling across zones
For a one-off event, give the time with a zone name and the UTC equivalent. For a recurring one, store the local time and the zone, never a fixed UTC offset, so it follows the daylight-saving rules of the place that owns the meeting.
To work with the underlying numbers, see the Unix timestamp converter.
Frequently asked questions
Where does the zone data come from?
From your browser's copy of the IANA time zone database. Results follow the rules known to that browser, so a change a government announces shortly before it takes effect may not be reflected until the browser updates.
Why does a row show +1 day or -1 day?
The same moment falls on a different calendar date in that zone. The label is relative to the date in the zone you entered the time in.
What do the green times mean?
They fall between 9:00 and 18:00 local time, as a rough guide to a reasonable meeting hour. It is not a statement about anyone's actual working day.
Does the Now button use my device's clock?
Yes. It reads your device's current time and shows it in the zone you have selected.