Convert Unix timestamp to date and date to timestamp, with UTC, local time, seconds, and milliseconds.
The converter turns Unix timestamps into UTC and local dates, and also calculates Unix seconds and milliseconds from a date. Values are processed in the browser, and shared links include the visible data in the URL.
Choose timestamp to date or date to timestamp. Use UTC for a deterministic result across devices; use local time only when the input is a browser wall-clock time.
The conversion runs in the browser. Shared values appear only in the generated URL.
Paste a value in seconds or milliseconds.
Seconds accept up to 3 decimal places. Milliseconds must be integers.
The link uses only the visible, normalized values on this screen.
UTC and Unix timestamps reopen the same instant on another device.
Unix timestamp counts seconds since 1970-01-01T00:00:00Z.
Date works with milliseconds; the tool also shows the seconds version.
UTC represents the stable instant. Local date depends on the timezone configured in the browser.
Conversion follows the ECMAScript Date range and does not model leap seconds.
It is a number that represents time counted from 1970-01-01T00:00:00Z, usually in seconds.
Unix systems commonly use seconds. JavaScript APIs and many logs use milliseconds.
UTC is the global reference for the instant. Local time is how that instant appears in the browser timezone.
The instant is the same, but computers in different timezones show different local times.
No. JavaScript Date and common Unix timestamps use POSIX-style counting without a leap-second table.
Yes. They appear as negative timestamps when they are inside the accepted Date range.