What Is a Unix Timestamp (Epoch Time Explained)
A Unix timestamp counts the seconds since 1 January 1970 UTC. Learn how epoch time works, why it is used, and how to convert it to a readable date.
A Unix timestamp (also called epoch time) is the number of seconds that have passed since 00:00:00 UTC on 1 January 1970. For example, 1700000000 is a moment in November 2023.
Why count from 1970?
That date, the "Unix epoch", was chosen as a simple zero point. Storing a moment as a single number makes it easy to compare, sort and do arithmetic on times without worrying about calendars or time zones.
Seconds vs milliseconds
Unix timestamps are usually in seconds, but JavaScript and many APIs use milliseconds (a 13-digit number instead of 10). If a converted date lands in 1970, you probably mixed up the two.
Time zones
An epoch value is always in UTC. The same timestamp shows as different local clock times around the world, but the underlying number is identical.
Convert one now
Turn a timestamp into a human date, or a date into a timestamp, with the timestamp converter. Scheduling recurring jobs? See Understanding cron expressions.