Hehe...when the sixth book came out, my partner and I were in Anaheim for the Disneyland 50th Anniversary celebration. We had preordered our books (yes, one for each of us) and picked them up at midnight from the bookstore in Downtown Disney. So, take a guess from that.
Then when the 4th movie came out, we saw it in a local (Sacramento) theater. Then, when we were on our December Disney trip (we have annual passes and he collects these Oswalski sculpture pieces of main street), we went to a local IMAX theater so we could see GOF in Imax. Going to see it in IMAX was so much worth it, too. Quite enjoyable and I noticed a few things I hadn't noticed before (like flitwick moving the bowl of olives and then putting his hand where the bowl had been...thus placing his hand in perfect position for a distracted Hagrid to stab said hand...and like how Cedric Diggory's body was in nearly EVERY shot of the graveyard scene after he was killed).