The first one was may 4th coasters after dark. The next one is family fall fun night some Friday night in September, possibly the 28th or the 14th since the 21st is a buyout. I really hope it's not the 14th since I won't be able to go.
Sept 21 according to coupon book. BAF 19.99 Coupon for "Fright fest preview night." I'd noticed when I had passes a couple years ago they had park marked as "Closed-Private event" on the calendar.