The American Heritage Dictionary defines "Christmastime" or "Christmastide" as "A festival observed from December 24, Christmas Eve, to January 5, the eve of Epiphany." Other sources include January 6, the Feast of the Epiphany, in the count. Scandinavians celebrate until January 13, St. Knut's Day, and depending on the reference, Christmas greenery can be kept up until Candlemas Day, February 2, but must be removed by then.
It's Christmastide, folks! Why are folks so all-fired quick to tear down their Christmas things the moment December 25 is over? It's Christmastide: go out and enjoy it! Some folks have spent weeks shopping, decorating, and baking. Now is the time to sit and enjoy it; make Christmas visits (after work, since we must) and still drink the eggnog and munch on a treat or two. Granted, the folks who've had their Christmas decorations up since before Veteran's Day may have pretty dusty ornaments by now. Why do folks put 'em up so early anyway when there's Thanksgiving to enjoy in November?
Even if you don't want to do the entire "twelve days of Christmas" routine, it would be nice not to see trees discarded in the trash at least until the day after New Year's. We always had the tradition that the Christmas lights stayed on all night both Christmasto guide the Holy Family to your house and New Year'sto see the new year in. Why not keep the winter doldrums at bay a little while longer with the beautiful welcoming lights and adornments and music?