It is also useful in that $duration takes a value in seconds. If you have a value in hours, then you'd have to manually calculate it to seconds before using $duration. With the script shown, you could easily convert that to accept all time amounts and convert them automatically to a duration.
Example:
//echo -a $dur(59h125m)
That may not be something you'd see often, but it's a valid code to show how to do it if it were needed.
For larger durations, the identifers $datediff and $DateXpander (not part of mIRC, but separate scripts) handle months and years in the durations. $datediff does somethings more easily, such as countdown timers, though $DateXpander can do that as well, but with more work. And $DateXpander does somethings more accurately, such as working with leap years. So if you are interested in having months/years in your durations and having them be accurate, you may want to consider looking into both of those identifiers to see which does what you need.
