Unix Timestamp Calculator
Select a date and time (UTC) to find the equivalent Unix timestamp in seconds and milliseconds.
The date and time you select are treated as UTC (Coordinated Universal Time).
How Unix timestamps work
A Unix timestamp counts the number of seconds (or milliseconds) that have elapsed since the Unix epoch — midnight UTC on January 1, 1970. It's a simple integer, making it easy for computers to store, compare, and calculate time differences without dealing with calendars or time zones.
This calculator treats your selected date and time as UTC. If you have a local time in a different time zone, convert it to UTC first (accounting for your UTC offset) before entering it here for an accurate timestamp.
Frequently asked questions
Why does the Unix epoch start on January 1, 1970?
This date was chosen somewhat arbitrarily by early Unix developers as a convenient reference point when the system was being designed in the early 1970s, and it has remained the standard ever since across nearly all computing systems.
What's the difference between epoch seconds and epoch milliseconds?
Epoch seconds is the traditional Unix timestamp format used by many systems and databases. Epoch milliseconds (seconds × 1000) offers finer precision and is commonly used in JavaScript and other systems needing sub-second accuracy.
Will Unix timestamps eventually run out?
Systems storing the timestamp as a signed 32-bit integer will overflow in January 2038 (the "Year 2038 problem"), but modern 64-bit systems store timestamps with far more range, making this a non-issue for current software built on 64-bit integers.