Christmas decorations: How soon is too soon?

When is it too soon for someone to put up their Christmas decorations? What is the earliest you have ever seen someone with theirs up? Does it make you sick or do you enjoy seeing them up so early? When do you put up yours?

So far this year I have seen white Christmas tree lights up on a bunch of trees at an auto shop and my neighbor has their Christmas tree standing and lit in their front window.

Bonus question: How soon should they be taken down after the holiday?