October and November is birthday season in my family. There are literally 9 birthdays in my immediate family during those two months, plus Thanksgiving. So I don't even start thinking about Christmas until after I've made it through the birthday gamut. If I did, I think I'd go crazy!
After Thanksgiving. I don't like to think of other holidays, as I want to enjoy the one I'm in right now. Once Thanksgiving is over and December arrives, then yes! I will gladly start Christmas then!
I start buying gifts in late October since I often buy gifts online and want to give plenty of time for them to arrive, but in terms of actual celebration, it depends on how desperate I am to start celebrating. As early as November is acceptable to me, but I try not to have tooooo much Christmas fun before actual December.
I do wish stores would wait until later to start blasting Christmas music and putting out decorations and stuff though, I feel like it must kind of suck for people who don't celebrate Christmas that everything is all Christmas-y as early as three or four months before actual Christmas.
I stopped celebrating Christmas a few years ago. This is due to researching the origins of the holiday and that it is pagan... Before I knew those things, I would start celebrating it somewhere around November where me and my family would start setting up the Christmas tree and play holiday music. Apparently, in the Philippines, the people there start celebrating the holiday three months early, which was back in September!