Im not entirely sure when it is yet, but basically it's where you sign up for jobs at Clementon. It usually takes place in the back by the picnic grove and you can apply for different positions throughout the park.. park services, operations, games, foods, waterpark etc.
If your really interested in going, my advice would be to get there as early as possible, as there are tons of people in that area that depend on the park for jobs each summer, and the line gets pretty rediculous.