Originally Posted by Blackcat31:
Never do or don't do something because of daycare parents. If you do, they will always expect it.
Just say, "Payment is due unless I am closed for vacation and this year I will not be closed that week."
Don't let the guilt get to you. 
I second what BC said. How would that be fair to you.
And BC, I’ve been using your saying “I’m not in the business of losing money” when I battle these scenarios myself!