I take two separate, full weeks, six months apart for less disruption to kids routines. I do not charge for those weeks as they are worked into my yearly tuition, in advance. (figured by 50 weeks instead of 52)
By "not charging" those two weeks, I don't have to deal with any push back or policing vacation payment.
I also take all Federal holidays,
paid. So, about 23 days per year. If I have to close for anything else (rare, 1x/5 years), I discount the day.
I also have the same schedule every year, so they know at least a year in advance.