Ive been told Halloween doesnt start until 5pm in a few places I lived. Last year we were ready, bored, and set out- at 445- and got 2 responses, that made me feel like we were intruding before we decided to wait til a lil after 5, figuring the "you're rather early, arent you" would stop once it got a lil later. QUOTE]
Where I grew up, trick or treating started at dark. Never during daylight hours. It's supposed to be a bit scary, not something done in broad daylight.
In this area, you also have to consider the impact on traffic of having everyone trying to get home from work in time to get their kids in costume and out the door to trick or treat. Halloween is one of the days each year you are guaranteed to be stuck in traffic if you try to leave your office early.