When I worked in the wonderful pizza business, even though I was a manager I had to join our delivery drivers on the streets on really busy nights, like Halloween. So, if you order a pizza for delivery tonight, keep the following in mind:
1. It's Halloween, and it's a Friday night. This means pizza places will be very busy, so don't get upset when it takes longer than 30 minutes.
2. Likewise, everybody else will have the same idea as you: that by ordering between 4:00 and 5:00, you'll avoid the crowds. Forget it. Dinner rushes on Halloween tend to hit very early. Your best bet, actually, is to order late.
3. Not only should you expect longer delivery times because of the sheer amount of business, but you should expect that delivery drivers will be going a lot slower due to all the kids out and about.
4. If you're not offering candy to kids, and thus you're leaving all your outside lights off so as to avoid having armies of people knocking on your door, please reconsider ordering your pizza for delivery. Consider ordering carry-out and going to get it yourself. It's a tremendous pain to locate the houses whose lights are shut off (because then the numbers on the door aren't legible), which means it'll just take that much longer for the thing to get to you. And in some areas, drivers might actually be trained to not deliver at all to houses with no lights on. (Or, maybe you could turn on the light while you're waiting for the pizza and stick a sign on your door saying that you're not offering candy.)
5. TIP YOUR DELIVERY DRIVER !!! Really, you should be doing this anyway, but Halloween is probably the most stressful night of the year for people who make their living schlepping pizzas around. They're under pressure to deliver hot food to people quickly, and not run over small children while they do it. So if your pizza is $10.50, don't just give the person $11 and tell them to keep the change. And don't think for one second they'll consider candy in lieu of a tip. (Well, if they're good at their job, they'll accept the candy and act happy about it. But it's really not a nice thing to do.)
6. Even better, consider actually going to eat in the dining room at the pizza place. In my experience, our dining room was always dead-as-a-doornail on Halloween nights, when Halloween fell on a Friday or Saturday.