If you are Catholic, you may be familiar with the phrases “Octave of Christmas” and “Octave of Easter.” These are fancy names for the special, eight-day celebration of these important feasts. The Church acts and celebrates as if Christmas literally lasted for 8 straight days, which sounds a bit like a Disney movie where Selena Gomez learns the true meaning of the holiday season.
The idea is not only that Christmas and Easter deserve such exuberance, but the extra days give us an extended chance to wrap our puny minds around the mysteries of Christ’s Incarnation and Resurrection (and then party).
January 1 is, then, the Octave Day of Christmas. The church designates this day as the Solemnity of Mary, the Mother of God, which is a Holy Day of Obligation. As a kid, this fact was the bane of my existence if Christmas happened to be on a Monday or something and we had to go to church FOUR TIMES IN EIGHT DAYS UUUGHHHH.
The eighth day, called the Octave Day, is celebrated as a repetition of the original feast. The connection with music is not hard to grasp here — C sharp and C sharp are the same note in different octaves. We celebrate Christmas anew on the solemnity of Mary, Mother of God, though at a different “pitch.”
In ancient Judaism, the eighth day after a boy’s birth was set aside for his circumcision, an important symbol of man’s covenant with God. It is during this rite that the boy receives his name. (Catholics celebrate the feast of Christ’s Circumcision on Jan. 1 and the feast of the Holy Name of Jesus on Jan. 2.)
In Catholicism, the “eighth day” has always signified the Resurrection and the new Creation. The Catechism says:
349. The eighth day. But for us a new day has dawned: the day of Christ’s Resurrection. The seventh day completes the first creation. The eighth day begins the new creation. Thus, the work of creation culminates in the greater work of redemption. The first creation finds its meaning and its summit in the new creation in Christ, the splendor of which surpasses that of the first creation.
St. Ambrose wrote that a baptismal font had eight sides
because on the eighth day, by rising, Christ loosens the bondage of death and receives the dead from their graves.
St. Peter wrote that
God waited patiently in the days of Noah, during the building of the ark, in which a few, that is, eight persons, were saved through water. And baptism, which this prefigured, now saves you (1 Peter 3:20-21)
Given these connections — God’s saving covenant with man, receiving a name, the idea of rebirth and a new creation, and the “eighth day” of eternal life — it is not hard to see why there is a long tradition of Catholic churches having octagonal baptismal fonts or baptistries.