And on the casting I personally guaranteed for a date when they will get a result. Rejections included feedback that helped candidates understand our decision and improve their craft.
This is in my opinion how you do things when you have a shred of respect for the people on the other side. Actors greatly valued how we did things.
If you can't live with the insecurity of knowing whether you're able to keep those dates, just make a pessimistic guess and add a few days on top. It is really not that hard.