I DON'T MAKE THE RULES, PEOPLE.
According to "experts", and by "experts" I mean 'The Journal of Environmental Psychology', they've put out a blog explaining that putting up your holiday decorations EARLIER, puts people in a better mood!
Seriously - decorations show your neighbors that you are accessible and according to Delish, 'people perceive people with holiday decor to be more friendly and cohesive.' Christmas brings back childhood memories and that leads to excitement, so put them up early! It's a way to reconnect with their childhood and nostalgia helps people also understand their identity.
Don't make fun of people who do this - maybe you should try it and see how things change!