More settings turn timer

Well for people like me that have 15 minute or 20 minute breaks, we wish to play for 15 or 20 minutes. However with the current system we can only pick 10 turns or 15 turns. (Making every turn 2 minute isn't really going to make me satisfied either. More turns = more fun in less time)

So I suggest:
-Able to pick 5 turns
-Able to pick 10 turns
-Able to pick 15 turns
-Able to pick 20 turns
-Able to pick 25 turns
-Able to pick 30 turns

I think this would satisfy me and some other players that do not have much time.