stay and scream?

[luvpooh]

If we have a pass for during the day and then buy the stay and scream pass, do we have to be in the park at closing to utilize it, or can we leave the park prior to closing, go to dinner, and then come back at the beginning of the regular event? We're not concerned per se about getting the head start, I'd just like to save the $48 since we'll probably buy the express passes...