That's really early. Kids don't ever come around here until it's dark, well after 5:30 anyway. I'd prefer they came earlier, but whatever.
Hubby, the dog, and I have a system. I buy the candy for the treaters. Hubby gives it out to the kids, and I hang out upstairs and play on the computer or watch tv. Hubby leaves outer glass door open, so the kids can see that we're home, and giving out candy. Dog sits in his favorite "lookout" spot, in the middle of our inside stairs (leading down to our first floor) and barks when the kids come near the front door. Hubby hears dog bark, and gets up from the sofa in the livingroom and gives out the candy.

(We shut off our porch light at 8:00, and that's it.)