[[A kid dressed up in a lab coat and goggles is standing on a neighbor's doorstep.]]
Kid: Trick or treat!
Neighbor: Nice Doc Brown costume, but today's October 30th.
Kid: Great Scott, I must have overshot!

{{Title text: Not enough houses on your block?  Just hit them at 30-year intervals from here to 2300 and get 10x the candy.}}