Borrowed this from mouseplanet... These are not set in stone...
"Walt Disney World's November operating calendar has been released, and it appears that the final night of Mickey's Not So Scary Halloween Party is one night later than expected. The final Halloween Party of 2012 will take place on Friday night, November 2, instead of Thursday night, November 1.
We also have the projected November dates for Mickey's Very Merry Christmas Party and have used them to further project the dates for December. The November dates appear to be November 9, 12, 15, 16, 25, 27, 29, and 30. Based on the apparent Sunday, Tuesday, Thursday, Friday schedule (as opposed to last year's Sunday, Tuesday, Wednesday, Friday schedule), we are projecting December's dates to be December 2, 4, 6, 7, 9, 11, 13, 14, 16, 18, 20, and 21.
The final dates will be released when tickets go on sale, which should take place within the next couple of weeks."