That's one of the falsehoods. Unix time is not equal to the number of elapsed seconds since the epoch, it is equal to N x 86400 + s, where N is the number of da

That's one of the falsehoods. Unix time is not equal to the number of elapsed seconds since the epoch, it is equal to N x 86400 + s, where N is the number of days that have elapsed since the epoch, and s is the number of seconds that have elapsed since midnight.