Solemnity of Mary, the Holy Mother of God - Holy Day of Obligation
On the 8th Day of the Octave of Christmas and at the beginning of the new civil year, the Church celebrates Mary as the Mother of God. One of the oldest titles for Our Lady, the Greek title Θεοτόκος (Theotokos), meaning "Bearer of God" was adopted by the First Council of Ephesus (431) as an assertion of the divinity of Christ.
This will be the only Mass celebrated on January 1 and there are no scheduled confessions this day.