Epoch Converter
Convert Unix timestamps to readable dates and back, in both UTC and local time, with seconds and milliseconds handled automatically.
Seconds or milliseconds. The unit is detected from the number of digits.
The other direction
Seconds, milliseconds and the 2038 problem
Unix time counts seconds since 1 January 1970 UTC. Ten digits is seconds, thirteen is milliseconds, and the gap between them is wide enough to guess reliably: a ten-digit value read as milliseconds would land in 1970. Java, JavaScript and most log shippers emit milliseconds, while Linux tooling and database epoch columns usually emit seconds.
A signed 32-bit seconds counter overflows on 19 January 2038. Anything still storing time in a 32-bit integer by then wraps to 1901. This matters now for embedded gear, old filesystem metadata, and any database column still typed as a 32-bit int.
Negative values are valid and mean a date before 1970, which is worth knowing because a corrupted or zeroed field often shows up as 1 January 1970 exactly.