[eluser]Colin Williams[/eluser]
Did you even look at mktime() and gmmktime()? You can also just do time() (or now()) + the number of seconds in the future
Code:
$future = now() + ($hrs * 24) * ($min * 60) * ($sec * 60); // You'll need to conditionally multiply what's in the parentheses
You shouldn't get hung up on simple math like this.