My Mother & Aunt used to tell us about how early the public Xmas decorations were in "their day". September was quoted, and I think it would be a shop or two, possibly a window display. Probably to remind people of the old "Christmas Club" where people put money in to a shop as a savings account to spend in the shop at Christmas.
I remember "Christmas Clubs" in (usually) local shops but haven't seen any lately. Credit cards and the "mortgage the future" culture killed that, and gave us this recession. Yea Yea its over, tell that to anywhere other than London (other Capital cities are available)