Hi, Cory!
Mickey's Not So Scary Halloween Party is probably my favorite specially ticketed event at the
Magic Kingdom Theme Park. It's a great evening of family Halloween fun, with Halloween themed entertainment, parades, and fireworks. Oh, and let me not forget the seemingly endless supply of trick or treats! We have always gone back to the hotel with more than enough candy to keep everyone happy for days.
You are correct that the dates have not yet been released, but if we go by historic precedence, the days of the party are usually Sunday, Tuesday, Thursday, and Friday. Of course, this is subject to change with the coming Halloween season, but it seems that they do try to offer as many dates as possible so that everyone who wants to attend the party has as many opportunities as possible to do so. I think that's why the season seems to extend a little further the past couple of years - even guests who have to head back to school after Labor Day still had a chance to make one of the parties.
I also always like to tell people that are worried about packing bags for the plane with big bulky costumes - two things - first, it's Florida, so you really don't need big and bulky. Leave the fluffy Winnie the Pooh costume in Pennsylvania until Halloween there. Second, there are many costume options available at the shops throughout the theme parks and resorts. You'll be able to put something together when you get there.
Wishing you a boo-tiful vacation!
Anna