What is a Unix timestamp?
A Unix timestamp counts the number of seconds that have elapsed since 00:00:00 UTC on 1 January 1970 — called the Unix epoch. It is a single integer that uniquely identifies any moment in time regardless of timezone, making it the universal standard for storing timestamps in databases and APIs.
To convert a timestamp to a readable date, divide by 86400 to get days, then add to 1970-01-01. In practice, browsers and programming languages provide built-in functions that handle this. Negative timestamps represent dates before 1970.