The kids at the party are watching the first Halloween. They start watching the movie sometime before the curfew, which is 9:00 p.m. During all the slashings and killings, we see glimpses of the movie Halloween. The scenes are out of order. Also, when Stu and Billy have Sydney in the kitchen, it's midnight, and the movie is still going. Halloween is not a three hour movie, and I don't believe anybody stopped it. They could have.