How to Convert Time Zones for a Specific Date and Time
Enter one or more comma-separated locations and an optional reference time, then review the local date, time, offset, and timezone details for each valid entry. For consistent results, supply a specific ISO-8601 datetime with an offset.
Overview
Use a multi-timezone converter when you need to compare a reference time across several locations. You can enter a comma-separated list of locations, provide a time, and review the resulting local date and time for each recognized timezone. The converter applies the timezone rules for the reference date, including seasonal offset changes when those rules define them. If you leave the location list blank, it uses New York, London, Tokyo, and Sydney as the default locations.
Steps
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Enter the timezone locations as a comma-separated list, such as
New York, London, Tokyo. Spaces around entries are trimmed, empty entries are ignored, and the list can contain between 1 and 30 nonempty entries. You can use recognized location names or IANA timezone identifiers. -
Set the reference time. Leave it blank to use the current UTC time at the time of use, enter
HH:MM, or provide an ISO-8601 datetime. An ISO datetime without an offset is interpreted as UTC. If it includes an offset, that time is converted to UTC before the locations are calculated. -
Submit the conversion. For each recognized timezone, review the local clock time, local calendar date, UTC offset, 12-hour display, ISO-formatted local datetime, and timezone abbreviation.
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Check the status of every location you entered. An unrecognized entry is omitted from the converted locations and identified separately, while valid entries can still produce results. If no supplied entry resolves to a valid timezone, the operation is unsuccessful.
Understanding the result
Treat the output as a comparison of civil times based on one UTC reference instant. The local calendar date may differ between locations, so check both the date and the clock time before scheduling or comparing events. The listed UTC offset and abbreviation provide additional context for each converted location. Results can vary when the reference time is omitted because the current UTC time is used at the moment of invocation. For a repeatable comparison, supply a specific reference time, preferably with an offset or as an ISO-8601 datetime.
Worked example
You are checking how one scheduled meeting appears in New York, London, and Tokyo on January 15, 2025.
Enter New York, London, Tokyo and use 2025-01-15T15:00:00-05:00 as the reference datetime, then submit the conversion.
The result contains a converted entry for each valid location, with its local clock time, local calendar date, UTC offset, 12-hour display, ISO-formatted local datetime, and timezone abbreviation. Any unrecognized entry is listed separately.
Limitations
- The converter does not guarantee a converted row for every supplied name: unrecognized entries are skipped, and input with no valid timezone is unsuccessful.
Common errors
- A location may be omitted when its spelling is not recognized and it is not a valid IANA timezone identifier. Correct the entry by using a recognized location name, such as
ChicagoorTokyo, or provide the appropriate IANA identifier.
FAQ
Can I include several timezones at once?
Yes, if the list contains at least one valid timezone. Unrecognized entries are omitted and identified separately, while valid entries can still be returned. If none of the entries is valid, the operation is unsuccessful.
What happens when I do not enter a reference time?
Leave the reference time blank to use the current UTC time at the moment of invocation. Because that time changes, repeated conversions can produce different results.
Which reference time format should I use for a repeatable conversion?
Use an ISO-8601 datetime with an offset when you need a specified moment. An ISO datetime without an offset is treated as UTC, while an offset datetime is converted to UTC before local times are calculated.