Since it falls on a Saturday this year, I'm figuring that the kids in my neighborhood will probably be starting after lunch around 1:00pm. That's the earliest I'll take my kids out. The latest I will (or have) kept them out is 9:00pm - no later. I don't hand candy out after 9:00pm unless it happens to be an unusually warm night and there are still a bunch of them out later than they normally would be. Most of the younger kids are in by that time already.
I'm already dreading those "early birds" that may start earlier. Just hoping they don't come too early - Saturday is the only day I get to sleep late :-)
Hope this answer helps - Happy Halloween!