[toast0]

I think you two are talking past each other.

> That's not true. Unix time is specifically defined as "A value that approximates the number of seconds that have elapsed since the Epoch."

It's missing 27 seconds that elapsed since the epoch. (Plus whatever happened with rubber seconds before 1972). Maybe that fits within the definition of approximate.

But if you need to record events that happen on a leap second or the second before a leap second, unixtime is unhelpful.

If you want to record a duration that includes a leapseconds, unixtime is unhelpful, although if the duration is long enough, the difference may be of no consequence.