If you are there during christmas week, the parks are all open to their latest times. We have been there for that week-New Year's for the past 2 years. What makes it a bit hard to plan your PS even at 90 days is that often, official park hours are not posted yet. This happened to us when we called to eat at Cinderellas castel for dinner on 12/28/03. At exactly 90 days, they said the latest I could get was 5:45pm. I politely told her that I knew the park would be open until at least 11pm, but she said, sorry. I again, politely said no thank you. I called the 2 days later to make another PS(the park hours were now on the website) dand I was told that I could have anytime until 11:00pm at which time I booked 8:45pm. so moral is , the park hours need to be set on the official site before you can get late seating times. Otherwise, you can only book until the earliest possible closing time for the park. also, if it is a holiday (NYE, Christmas day) they will ask to secure it with a CC(did for us on NYE at Brown Derby), but you can cancel up to 48 hrs before without penalty. Just an aside-they also changed the EMH days during that week which also can cause a blip in you ps plans.
Connears