I think that's why Disney is also having a party on Tuesday night (to add to the coffers since Halloween is falling on a Monday this year).
I should probably use some common sense (and Google) and look this up myself, but isn't there always a party on 11/1, regardless of what day of the week Halloween falls on?
I know it's a money making thing (which is why there are Halloween parties in mid-September) but I like the idea of an 11/1 party. Of course, I'm a Halloween lover, and I see nothing wrong with having an extra day to celebrate, so my opinion is slightly skewed.