Formula
Unix time counts seconds from the UTC start of 1970:
Unix time = seconds from 1970-01-01 00:00 UTC to the date
The result is midnight UTC on the date you enter, not a clock time during that day.
Assumptions
- The date is read as UTC.
- Midnight starts the date.
Worked example
Midnight UTC on January 1, 2026 is Unix time 1,767,225,600.
Input definitions
- UTC date
- The calendar date, interpreted in UTC.
Limitations
Leap seconds are not added. A time of day other than midnight is not accepted.
Questions
Why midnight?
A date alone has no clock time, so the page uses 00:00 UTC.
Does this include my time zone?
No. The date is UTC. Use the time zone page to shift a clock.