A repeated hour in New York
November 3, 2024 at 01:30 occurs twice in America/New_York. The earlier occurrence is 05:30 UTC and the later is 06:30 UTC. The tool waits for your choice rather than guessing.
2026-07-02
Thu, Jul 2, 2026, 01:00 GMT+9
UTC−04:00America/New_York offset at this instant
UTC+09:00Asia/Tokyo offset at this instant
Same instant in UTC: 2026-07-01T16:00:00.000Z. The target date may be earlier or later than the source date.
Uses your browser’s IANA time-zone data for years 1900–2100. Rules and future projections depend on the installed data version. Missing wall times are rejected, and repeated times require a choice. Abbreviations such as CST are not reliable location identifiers.
Calculations run in your browser. Dates and settings are not uploaded by this tool.
How to use the Time Zone Converter
- 01
Enter the calendar date and 24-hour time in the source location. Use IANA identifiers such as America/New_York or Asia/Tokyo.
- 02
Choose the target location. The result shows its complete date, local time, and UTC offset at the selected instant.
- 03
If the source time repeats, choose the earlier or later occurrence using the listed UTC offsets and UTC instants. A nonexistent time requires a different input.
- 04
Copy the conversion, or swap zones to keep the selected instant and reverse the display.
Examples
A time that never occurred
March 10, 2024 at 02:30 does not exist in America/New_York because the local clock jumps forward. This input is rejected instead of shifted silently to another clock time.
The next day in a quarter-hour-offset zone
January 1, 2024 at 23:30 UTC is January 2 at 05:15 in Asia/Kathmandu. The full target date is essential when a conversion crosses midnight.
Wall time and exact time are different inputs
A wall time combines a local date and clock reading. A location’s offset rules map that reading to an exact instant, but an offset transition can create zero or multiple matches. The calculator checks possible offsets near the date and round-trips each candidate to the source wall time. It reports a gap or offers every matching occurrence rather than applying an invisible default.
Use a location identifier instead of an abbreviation
Names such as America/Chicago and Asia/Kolkata identify rule sets. Abbreviations can be shared by unrelated locations and do not reliably specify daylight-saving behavior. The offset shown in the result applies to the selected instant, rather than being treated as a permanent difference between two places. The two locations can change clocks on different dates.
Your installed time-zone database matters
Conversions use browser Intl data rather than a remote time service. Governments can revise clock rules, and your software may not yet include the latest change. Future conversions are projections under the installed rules. Keep your browser and operating system current, and confirm critical future appointments against the relevant local authority or calendar service.
What to know
- Missing source wall times are rejected. Repeated source wall times require an occurrence choice. No recurring-event schedule is generated.
Common questions
Why must I choose earlier or later?
The same source clock reading can occur twice after an offset moves backward. The two choices identify different UTC instants and can produce different target times.
Are all transitions one hour?
No. The candidate matching works with the actual offsets in the installed data, including half-hour transitions and skipped calendar dates.
What happens when I swap zones?
After a valid conversion, the displayed target wall time becomes the source and the selected instant is retained. The output then describes the original location.
Which years are supported?
Source dates from 1900 through 2100 are accepted. Historical accuracy and future rule changes depend on the browser’s data; this tool does not bundle an independently updated database.