This is a Public Service Nag:
January 1 is an Octave Day of the Nativity of the Lord, and the Solemnity of Mary, the Holy Mother of God.
It is a Holy Day of Obligation. (Translation: Faithful Catholics are Obliged to attend Mass today!)
Incidentally, the Basilica of St. Mary Major houses relics from the crib of Jesus in an ornate container made of gold and silver, which is shaped like a crib. According to the Catholic Encyclopedia, the relics were likely brought to Rome in the pontificate of Pope Theodore (640-649), who was a native of Palestine. The relics consist of five pieces of wood board taken from a Sycamore tree, “of which there are several varieties in the Holy Land.” These pieces might only have been “mere supports for the manger itself, which was probably made from the soft limestone of which the cave was formed.” The relics are exposed for veneration by the faithful every Christmas Eve.