I have several friends who have already started Christmas decorating! As soon as Halloween ends, bam! It's Christmas everywhere! I even know people who are already listening to Christmas music.
Christmas is special, & I think it loses some of its "special-ness" when all the Christmas decor comes out in October. For me, by the time Christmas is actually here, all the decor looks tired & dismal if we've been looking at since before Halloween.
I don't like to rush the seasons. November is still fall, & Thanksgiving is still a fall holiday.
I LOVE Christmas decorating, but we've always waited until the Friday & Saturday after Thanksgiving to start decorating. If we're not hosting Thanksgiving at our house, we *might* start decorating the weekend before Thanksgiving just so it's done & we can relax after Thanksgiving - but that's the earliest we'll ever decorate. This year, we're hosting Thanksgiving, so, the day after Thanksgiving, I'll put away all our fall & Thanksgiving-specific decorations & then bring out the Christmas decor.
Sorry! Early Christmas decorating is a pet peeve of mine! LOL!
To answer the question, we decorate for Christmas the weekend after Thanksgiving. We put away the Christmas decorations by the 12th day of Christmas (1/6). Our daughter's birthday is January 5th, so, some years, depending on what our plans are for her birthday, we will put the decorations on January 1st.