Up to what time can you expect people to knock on your door? Does it go all
night? or is there some sort of accepted time after which you shouldn't be
disturbed?

Here, it's about from 6 to 8 p.m. When you're out of candy, you turn the porch
light off. After 8 p.m., when the trick-or-treaters are bigger than you, and
their cigarettes fall out of their pockets when they bend over, it's time to
turn off the porch light.

Sherry