Word from Carl Sommer, author of We Look for a Kingdom: The Everyday Lives of the Early Christians:
I’m sending you this link now, while it’s still on my mind, because the archaeologist expresses a new iteration of a theory that’s been around for almost two hundred years. The theory is evocative, and unobjectionable in most of its forms, but it is almost certainly false, since our old friend Hippolytus of Rome wrote about celebrating the birth of Christ on December 25 almost a hundred years before the Council of Nicea … I’ll look up the reference from Hippolytus after the New Year. Whatever the origin of the December 25 celebration of Christmas, it clearly predates the Council of Nicea, at least in Rome.
I was unaware of any testimony from Hippolytus, though I knew about Clement of Alexandria and Julius Africanus, and they go back still further. Thanks to Carl for clueing us in.