In Calgary in the height of summer, sundown is so late that drive-in movies can't start until after 11pm. With the standard double-feature, you didn't get out of there until 3am. I think they've all closed down by now, however. It was really a terrible way to watch movies. I remember one show that was entirely on an airplane, and fairly darkly lit. You could hear it, but you had no idea what was going on.