2 little ideas:
1: When you start production, or heal army or whatever action that uses a slider, maybe it could be made that the slider starts at the right side (maximum), in stead of the left (minimum). Makes it easier and faster to start production.
2: A 2nd input field right under "how many should be produced", that says "how long do you want to produce". Maybe with a dropdown menu that displays the hours. Saves me some mental math, so it's easier and faster to start production.
Yes, i'm lazy!