Question about the US school system/holidays

Americans on my flist, how long does the summer vacation typically last for students just out of high school before they start college in the fall?

Beta request for Yuletide treat

Mostly for the grammar/spelling aspect. I'm not done writing it yet, but it should be around... 3'000 or 4'000 words, I think. I'd like to have it up by the 22nd, if at all possible.

Comments screened in case someone wants to know the fandom.