There are answers to this question that depend on everything from Prince Albert to the opinion of tree growers to something called Adelaide Pageant Day. Whether you're undecided on the best time to put up your Christmas tree or are merely looking for reinforcement for your preferred date, at least one of these timing traditions is bound to work for you: The ultimate etiquette authority, Miss Manners , doesn't specify when you should put up the tree, but does note succinctly that it isn't done before Thanksgiving.