> OK yes, it's more common to use POSIX 'ticks' to represent an instant in time. The point is: Type 1 is an instant in time I'm not sure what a "tick" is, but

> OK yes, it's more common to use POSIX 'ticks' to represent an instant in time. The point is: Type 1 is an instant in time I'm not sure what a "tick" is, but POSIX time often purports to be the number of seconds (or similar) since 1970, (and thus, represent an instant in time) but in practice it isn't; that's the point of the parent poster: it's precisely the definition that he or she gave. (It's the number of days times a constant, etc.) While usually POSIX time represents an instant in time, it becomes ambiguous during leap seconds, and duration calculations with POSIX times will almost invariably be just arithmetic on the underlying value, which is going to be wrong over certain intervals (any interval crossing a leap second). For the most part, nobody notices, but this is where and why weird bugs crop up.