The distribution seems bi-modal. My wife was a teacher, and she had maybe one free week the whole summer, between development classes, curriculum work, and so on. On some summer days I would leave work at 7pm and then join her in her classroom until 8 or 9pm where she was just finishing up a 12 hour day.

Then there were other teachers at the school who took off on the last day of school and you didn't see them again until the week before school started. Those were the teachers that were still teaching material from 30 years ago that all the parents dreaded their kids getting.