What is epoch or unix time?

[maltiger]

Link: https://en.wikipedia.org/wiki/Unix_time

A lot of us do not know what epoch means? In this context the definition is:

A point of time distinguished by a particular event or state of affairs; a memorable date.

It is the number of seconds passed since beginning of 00:00:00 UTC Thursday 1, January 1970 minus the number of leap seconds.

This applies to all Unix-like systems.