Hi Kim,
I have great news!
The Parade, Fireworks and other Nighttime Spectacular show schedules have already been released on the Walt Disney World website for September 2016.
For example, according to the Park Calendar for
September 28, 2016, at the Magic Kingdom park, the Main Street Electrical Parade will be taking place at 8:00 PM, Celebrate the Magic will be taking place at 8:45 PM and Wishes Nighttime Spectacular will be taking place at 9:00 PM. At Epcot, IllumiNations: Reflections of Earth will be taking place at 9:00 PM and over at Disney's Hollywood Studios, Fantasmic! will be taking place at 8:00 PM.
You can check the specific dates of your visit by hovering your mouse over where it says "Parks and Tickets" on the Walt Disney World website. On the right hand side of the highlighted box, click on where it says "More Hours" in blue and then click on the calendar icon situated after the displayed current date and select the first date of your stay. From here, you can click on each individual Theme Park to access the times that the Parades, Fireworks and other Nighttime Spectacular shows will be taking place on that particular day. You can then do the same day for each of the remaining dates of your stay by clicking on the right arrow situated after the calendar icon.
Wishing you a magical trip filled with memories which will last a lifetime!
Emma