Unix timestamp converter - epoch time to date and back

A Unix timestamp (epoch time, POSIX time) is the number of seconds elapsed since 1 January 1970, 00:00:00 UTC, ignoring leap seconds. The same moment has the same timestamp everywhere in the world - the time zone only matters when you display it as a date.

Example: 1,767,225,600 is midnight UTC on 1 January 2026, which is 19:00 on 31 December 2025 in New York (EST, UTC-5) and 09:00 on 1 January in Tokyo (UTC+9).

Unix systems, PHP (time()), Python (int(time.time())) and most databases use seconds - 10 digits for current dates. JavaScript (Date.now()) and Java (System.currentTimeMillis()) return milliseconds - 13 digits. Go and some logging systems use nanoseconds. The converter guesses the unit from the magnitude: below 10¹¹ it is seconds, below 10¹⁴ milliseconds, below 10¹⁷ microseconds, above that nanoseconds. You can also pick the unit manually.

• JavaScript: Math.floor(Date.now() / 1000)
• Bash: date +%s, and back with date -d @1767225600 (GNU) or date -r 1767225600 (macOS)
• PostgreSQL: SELECT extract(epoch FROM now()) and to_timestamp(1767225600)
• MySQL: UNIX_TIMESTAMP() and FROM_UNIXTIME(1767225600)

For APIs and JSON, use ISO 8601 in UTC: 2026-01-01T00:00:00.000Z, where “Z” means UTC. It is unambiguous, sorts correctly as text and is parsed by every language. HTTP headers such as Expires and Last-Modified use the RFC 7231 format: Thu, 01 Jan 2026 00:00:00 GMT. Both are shown with a copy button.

When converting a date to a timestamp, decide whether the date you typed is local time or UTC - the difference is your UTC offset, and daylight saving time changes it twice a year in most of Europe and North America.

When a timestamp is stored as a signed 32-bit integer, its maximum value is 2,147,483,647 - 19 January 2038, 03:14:07 UTC. One second later the counter overflows to a negative number and the date jumps back to 13 December 1901. Modern operating systems and languages use 64-bit timestamps, which last for billions of years, but the problem still affects older embedded devices, some file formats and database columns declared as 32-bit INT. Need date arithmetic rather than raw timestamps? Try the days between dates calculator.