I'm putting my money on there being one on the Saturday but would lean towards there not being one on the Friday.
In 2013 they did 2 nights back to back on the Wednesday and the Thursday if I am not mistaken but they are both nights where the park would normally shut pretty early with no fireworks anyhow. But then last year I am seeing conflicting reports on whether there was a party on the Wednesday the 29th or just the Monday (27th) then the Friday (31st)?
So for me the question is will they:
a)Do the last parties Wed and Friday with no party on Halloween (least likely imo)
b)Do parties both Fri and Saturday-if they do this will they open later than previous years on the Thursday to allow day guests a chance to see the 60th anniversary fireworks?
c)Do a Party on the Wednesday and the Saturday?
d) Do a Party the Thursday and the Saturday?
e) Do the party on Monday and Saturday.
Come Disney just tell us!!!!!
Personally what I will find frustrating is that if there is no party on 29th then I will need to wait until September to confirm park hours for that day and whether they will be as usual or extended with Fireworks as part of the 60th celebrations
There shouldn't be any conflicting reports about when parties took place last year. I don't know who is giving out incorrect or incomplete info. The info is right on page 1 of this thread (look at all of the red text, where it says "SOLD OUT"
http://www.disboards.com/threads/ha...ut-halloween-time-2015.3270919/#post-51326911.

There were parties on 10/27, 10/29 and 10/31. However, that doesn't mean that this year's schedule will be a replica of last year's. They added in an extra night last year, so there were a couple of Wednesdays thrown in that might not have been part of the schedule in the past.
When in doubt, remember to always come to the Superthread. I find that when a thread is dedicated to one specific subject all year long, every year, the info is more accurate and specific because that is all that is discussed and covered in the thread. When people get information outside of the Superthread -- or outside of any thread that is dedicated to a particular subject -- and random people (who may not closely follow that specific subject all year, every year) try to answer questions, they may not always present the full and complete picture, or they may get some of the details mixed up -- which then adds to the confusion for people reading the posts. Also, sometimes people don't want to post in a Superthread, but they take bits of info from the thread and try to repeat it or pass it on elsewhere, inevitably getting something mixed up in the translation.
So that's why I always recommend that people go to a Superthread or existing, established, active thread about any subject (whether it's WOC or Fantasmic or the GCH, or whatever) to get the best and most accurate info. Chances are, the people who follow and participate in those threads are people who either know a lot about the subject in question, or they have a big interest in it and want to know all there is to know.
In any case, your guesses are as good as mine on which scenario will take place for MHP! Even though I know we will likely get the confirmed, official schedule within the next couple of weeks, I do wish they would just tell us now and end our misery!

Another option is that the party could be held in DCA on some nights, and in DL on other nights -- although that seems much less likely and too cumbersome and confusing.
Having back-to-back parties on earlier weeknights is expected at some point, just because they'd be closing earlier on those nights anyway and the MHP closure would not be as extreme. Closing the park early on a back-to-back Friday and Saturday would be the real surprise.
There is no getting around the fact that MHP will put a dent in the schedule of the current 60th anniversary parade and fireworks (several Fridays are involved, and probably a Saturday), and Disney has obviously spent so much time and money on promoting the Diamond Celebration. Plus, Disney has said that the new nighttime shows will still be going on even during the holiday/Christmas season, but they never addressed Halloween Time and what would happen. It would be silly to charge folks for a party that features Paint the Night and Disneyland Forever -- because those are available to the general public and are not exclusive. And yet, having Halloween Screams fireworks on at least 14 nights (probably 15), with 6 of those being Fridays and Halloween being a Saturday, would interfere a bit with some the showings of PtN and DF.
Remember a couple of weeks back I was saying that it was so frustrating because I was looking for the thread that was on MiceChat last year in which the OP claimed that Mickey's Halloween Party would be moving back to DCA this year? I guess I was using the wrong search engine (Google failed me), because I could not find the thread at all -- no matter what combinations of keywords I used from what I remembered of the thread.
Anyway, using a different search engine tonight (Bing), I found the thread where the rumors first started!!!!!!
This is also the same thread in which a totally different person mentions that people at the MHP training were told there are "BIG" changes coming to MHP this year. Here is the 2014 thread (which has not been active since 2014, and actually, I can tell that some of the posts were deleted; I remember that the OP posted again, and yet that post seems to have vanished):
http://micechat.com/forums/disneyland-resort/198352-mickey-halloween-party-moving-dca.html
And this was the MiceAge Disneyland Update article (also from 2014) in which it is mentioned that Team Disney Anaheim was supposedly tasked with adding on two weeks of extra Halloween parties in September 2015 and an extra few parties in October:
http://micechat.com/85860-miceage-update-bridge-to-nowhere/comment-page-2/
Anyway, these are old rumors and no new rumors have come out this year, but I just wanted you guys to see for yourselves exactly where the rumors initially came from!