This is totally a random post.. I just read a post (not on this board), and a bride mentioned she had booked her hair and make-up 12 months in advance. A lot of posters commented that she had been duped, bet they took a credit card deposit, don't fall for that scam etc etc.
I work in a very busy, very popular salon, and we can really only do 1 wedding per Saturday. We don't take deposits (so no scam) but do highly recommend booking early. All it takes is another bride to book her wedding party in... If you know your date, and know who you want to do your hair/make-up (have a favourite salon), just book it. Yes, even if it's 12 months out, we do not think you are weird (as PP told a bride). The same goes for your Christmas appointments! (although it is Summer vay-kay here at xmas, and it also is there for summer wedding season, so that could also account for the totally unasked for advice I am giving strangers on the interweb haha)
BTW - I am not trying to advertise myself as a vendor, I don't live in the US/UK and I am not trying to solicit business in anyway. Please don't ban me haha.