Unofficially you can start to guess the dates of the parties when the November travel agent calendar is released. If the MK closes at 7:00 pm, it's a good bet that it'll be a party night (except Nov. 1, which, if MK closes at 7:00 pm is probably the last MNSSHP party).
Right now the TA calendar are updated through August 2014. I would guess that the November calendar will come out in mid-April.
Last year the tickets went on sale May 1st, so the dates had to have been announced a bit before that.
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