Remind HN: Unix time is Not the number of elapsed seconds since 1970-01-01 00:00

Instead it is the number of seconds that have elapsed since 1970-01-01 00:00:00 NOT COUNTING LEAP SECONDS. This means it is neither a linear, nor a unambiguous representation of time.

This should be kept in mind when developing time sensitive software to prevent major errors!

Check out https://en.wikipedia.org/wiki/Unix_time for a more detailed explanation.