You can book earlier for tours. I know this because I read Monday on another thread about this -and I'd been waiting for "90 days out" for our next trip to book the Family Magic Tour.... and I called today (Tuesday) and booked this tour for June 16. So you definitely can book it before 90 days and in fact I'd recommend it... she actually acted like I was lucky that I was able to get our party of 4 on that tour for that day (which is good because I wanted to do it on my daughter's birthday!)
Oh and everything I have read says you have to pay at the time of booking. When I booked it she told me that too- and took my credit card info... but then at the end of the conversation she reminded me that I have to cancel with atleast 48 hrs notice "in order to not be charged".
??
So I don't know if that means they take the amount now and won't CREDIT you the amount if you don't cancel in time, or what.