I may be wrong but I believe it occurs at the time the park closes. If you take your time leaving the park, you'll be entertained to the constantly changing colors of the castle. At the very close of the park, they also play some special Disney music and thank you for spending the day at the park. We've been fortunate enough to have been in this position a couple of times and it is really special walking down an empty Main Street and looking back at the gorgeous castle. If you are with someone you love, you'll surely be kissing! It is a magical moment and one you'll remember if you get a chance to experience it.