I tell parents that payment is by enrollment not attendance so they must pay even if their child is not in attendance (if you don't make parents pay many will take advantage really quick and you wont have a steady income).
On my end they pay for stat holidays but they don't pay me if I am closed for any reasons. I don't feel comfortable making parents pay me if I am not working but everyone is different.
Yes, this is my policy too. (I have all teacher families as clients and am closed all summer, 2 weeks at Christmas and March Break; while my husband, also a teacher, is off too).
Children are great imitators.
So give them something great to imitate.