Usually early to late August. My big gripe lately is that summer vacation is a bit too long. I think it'd be nice if the school year was split into either 3 or 4 equal parts, with approximately equal sized breaks between them. Maybe something like 2 weeks for Christmas, 3 weeks fall and spring, and 3 or 4 weeks for summer. The problem I see is that after summer break people forget huge chunks of the previous syllabus and we spend the first weeks often reviewing what was done a major part of a year ago. I made the same mistake in graduate school one time and it took me a month or two to get back up to speed with the topics enough to start my thesis properly.

It's not some random idle thought, though. I really think we need a pretty hard core school rework. American kids are not making it to graduate school. They're not benefitting from the massive amount of tech jobs in the USA. Or in general, from the powerful industry we have. But most importantly, on the global scale our average student just isn't competing with foreign systems. A large part of this is cultural (i.e. seeing it as funny to be bad at math), and a large part of it is not respecting teachers properly. But I think another large part is that we've dug ourselves deep into the rote way of learning things like math and history instead of the proper critical thinking way. I know this is in part due to standardized tests, but we need some sort of new method other than forcing teachers to teach algorithms instead of mathematical reasoning and historical nuances instead of historical date lists. Etc.