What I am trying to say is why limited set of options?
Seems odd that I can only choose 1 hour or daily, what if I wanted 8 or 12 hours? In my particular case I would like 1 month.
Would it not be better to have a number box and Days/Hours/Minutes drop down.
So In this example I can put 8 in the box and select hours or 30 and select days?