Malorie:
Best wishes for your wedding next year!
Typically, the Halloween/Harvest decorations tend to be up a day or two before the first
Mickey's Not So Scary Halloween Party. Both the resorts and the theme parks get into the spirit with pumpkins, leaves, and the like. Our family has made it a tradition to visit during the fall season for the past several years and love the cooler temperatures, lower crowds and fun decorations that are more on the festive than spooky side.
This year, the first party was held on September 14, however, in earlier years the parties have begun even sooner in the month of September. The schedule is usually posted in April, so I'd recommend keeping an eye on the link above for a more specific date.
Wishing y'all a magical wedding day!
Whitney