Timezone & Epoch
Unix timestamps and time zones
Convert Unix epoch seconds to a date in a chosen IANA time zone, or convert a local date-time to epoch seconds. Unix time counts elapsed seconds from 1970-01-01 00:00:00 UTC.
Formula and method
Epoch seconds = milliseconds since the Unix epoch ÷ 1,000.
Worked example
Epoch 0 represents January 1, 1970 at 00:00:00 UTC, though its displayed local time depends on the selected zone.
How to interpret the result
A Unix timestamp identifies one instant worldwide; a time-zone display is a local representation of that instant. Converting a local date-time in the other direction can be ambiguous during a daylight-saving fall-back, when one clock time occurs twice, or invalid during a spring-forward gap.
Important limitations
- Daylight-saving offsets depend on the date and zone.
- Ambiguous local times near clock changes require extra care.
Common questions
Are Unix timestamps measured in seconds or milliseconds?
This tool uses seconds. JavaScript and some APIs commonly use milliseconds, which are 1,000 times larger. Check the digit count when a converted date is unexpectedly far in the future.
Does a timestamp contain a time zone?
No. It represents elapsed time from the UTC epoch. A time zone is applied only when formatting that instant for display.
Related tools
Method and examples reviewed September 8, 2026.