A Unix timestamp (also known as Epoch time or POSIX time) is the number of seconds that have elapsed since January 1, 1970, 00:00:00 UTC. It's widely used in programming and databases to represent points in time.

Unix timestamps in seconds are 10 digits long (e.g. 1711027200), while millisecond timestamps are 13 digits (e.g. 1711027200000). JavaScript's Date.now() returns milliseconds, while most Unix systems use seconds.

32-bit systems store Unix timestamps as a signed 32-bit integer, which overflows on January 19, 2038 at 03:14:07 UTC. Modern 64-bit systems are not affected. This tool supports the full range of JavaScript Date.

Yes. All conversions happen entirely in your browser. No data is ever sent to any server. You can verify this in the Network tab of your browser's developer tools.

This tool accepts Unix timestamps (seconds or milliseconds), ISO 8601 dates, RFC 2822 dates, and common formats like "2025-03-21 12:00:00" or "March 21, 2025".