JugglingReferee wroteIn past years, it's been early May.
In the words of the late Ed McMahon, "You are correct, sir."
I did some research on the NFHS website. The press release announcing the 2009-10 NFHS rule changes (End-of-game Replays Approved) came out on May 11, 2009.
Twenty-five days and counting.