Move accurately between epoch time and human-readable dates. Detect seconds or milliseconds automatically and convert wall time in real IANA timezones.
Use a common reference point, then adjust it above.
Unix timestamps traditionally count seconds since 1 January 1970 UTC and are usually 10 digits today. JavaScript and many APIs use milliseconds, commonly 13 digits. Auto detect handles both while the unit selector lets you override ambiguous values.
The epoch value itself has no timezone. A timezone only changes how that instant is displayed. When converting a calendar date back, the selected timezone matters because the same wall-clock time occurs at different instants worldwide.
Some local times are skipped or repeated when clocks change. This tool validates the resolved wall time and warns when a selected time does not exist. For audit logs and APIs, prefer UTC or include an explicit ISO offset.
Unix time is the number of elapsed seconds since 00:00:00 UTC on 1 January 1970, excluding leap seconds.
Yes. Dates before the epoch use negative timestamps, although application and database support can vary.
The conversion runs locally in your browser. A usage event is recorded when you press a conversion button so ZeeSharp can enforce plan limits.