Unix time is a date-time format used to express the number of milliseconds that have elapsed since January 1, 1970 00:00:00 (UTC). Unix time does not handle the extra seconds that occur on the extra day of leap years.
What does date do in Unix?
date command is used to display the system date and time. date command is also used to set date and time of the system. By default the date command displays the date in the time zone on which unix/linux operating system is configured. You must be the super-user (root) to change the date and time.
Why do we use Unix timestamp?
Unix time is a way of representing a timestamp by representing the time as the number of seconds since January 1st, 1970 at 00:00:00 UTC. One of the primary benefits of using Unix time is that it can be represented as an integer making it easier to parse and use across different systems.