Hello Courtney! Welcome to the Disney Parks Moms Panel.
My family attended the
2017 Mickey's Not So Scary Halloween Party last month and had a "Spook-tacular" time trick-or-treating, meeting dressed-up Disney Characters and enjoying all of the Halloween festivities the party provides.
While the official start time for Mickey's Not So Scary Halloween Party is 7pm, Guests are often welcome to enter Magic Kingdom earlier than the scheduled start time (without regular Theme Park admission) to get ready to hit the ground running when the party begins. There will be a special queue for Guests celebrating Mickey's Not So Scary Halloween Party, however Walt Disney World Resort does not have a preset time for when Guests may begin entering.
Basically, when the special queue is set up and the wristbands are being given out, Guests can approach the Ticket Gates and ask to enter the Magic Kingdom. While I have heard of Guests entering as early as 4pm on nights when Mickey's Not So Scary Halloween Party is in fulls wing, it is not guaranteed that Guests will be granted admission at that time.
When my family went, we made it to Magic Kingdom at 5pm and were granted admission immediately using our
Mickey's Not So Scary Halloween Party Special Event Tickets.
Have a Happy Halloween on Main Street, U.S.A.!
~Todd