Today's (not the) Octave Day of the Epiphany feast, of the Baptism of Our Lord, marks the formal end of the Christmas season in the 1962 calendar. The greater Christmas season continues, however, for as the Baronius Missal comments on the season after Epiphany:
"This period, which begins the day after the Octave of Epiphany, is an extension of Christmastide..."
The Office readings for today includes this sermon by St Gregory Nazianus (Second Nocturn):
(Reading 5): I am not able to restrain the outbursts of my happiness. I feel changed and elated. I forget my own meanness while I undertake and try to discharge the office of the great John. It is true that I am not the Forerunner, but at least I come from the desert. Christ is enlightened, or rather, He enlighteneth us with His own light. Christ is baptized; let us go down with Him into the water, that we may come up with Him.
(Reading 6):John is baptizing. Jesus cometh. He cometh that He may make holy him who baptizeth Him; He cometh to bury the old Adam in the waters; He cometh to hallow the blessed flood of Jordan. He Who is Flesh and Spirit cometh to open for all that should ever be baptized that power of generation whereby new peoples are constantly begotten of water and the Holy Ghost. The Baptist will not receive Him. Jesus striveth with him. I, saith John, have need to be baptized of thee. Thus speaketh the candle to the Sun, the voice to the Word.
(Reading 7): Jesus came up out of the water, having, in a manner, washed the whole world, and brought it up with Him. And He saw the heavens opened not divided, even those heavens which Adam had once shut upon himself and us his descendants, when the cherub's fiery sword barred the gates of Paradise.
(Reading 8): And the Holy Spirit bare witness, witness unto Him Who is of One Substance with Himself. And witness was given from Heaven, unto Him that came down from heaven.