Tool
Unix Timestamp Converter
Convert between Unix timestamps and human-readable dates instantly. Live epoch clock, auto-detects seconds vs milliseconds, supports all IANA timezones.
What is a Unix timestamp?
A Unix timestamp (also called epoch time or POSIX time) is the number of seconds elapsed since January 1, 1970 00:00:00 UTC, not counting leap seconds. It is the universal standard for storing and comparing moments in time across all programming languages and operating systems.
Seconds vs milliseconds
Most Unix timestamps are in seconds (10 digits, e.g. 1700000000). JavaScript's Date.now() and many web APIs return milliseconds (13 digits, e.g. 1700000000000). This converter auto-detects which format you're using based on the magnitude of the value.
Why January 1, 1970?
The Unix epoch was chosen by the developers of the Unix operating system in the early 1970s as a convenient reference point. It predates most modern computers, so almost all useful timestamps are positive integers.