Unix timestamp converter

Turn an epoch timestamp into a readable date, or a date into a timestamp. Detects seconds, milliseconds, and more.

What a Unix timestamp is

The number of seconds since 1 January 1970 at 00:00 UTC, not counting leap seconds. It’s the same everywhere in the world at the same moment, which is why logs, databases, and APIs use it.

Seconds, milliseconds, or more

Unix tools and most APIs use seconds (10 digits for current dates). JavaScript’s Date.now() and Java use milliseconds (13 digits); some databases and tracing tools use microseconds (16) or nanoseconds (19). The converter guesses from the number of digits; pick the unit yourself if it guesses wrong.

On a Mac, in Terminal

date +%s                  # the current timestamp
date -r 1735689600        # a timestamp as a date in your time zone
date -u -r 1735689600     # the same in UTC

Updated 25 September 2026