Comment Solemnity of Mary, Mother of God (Score 2) 157
I celebrate the new year by attending Mass for the Solemnity of Mary, Mother of God.
This isn't really "Good-old Gregorian January 1st". When Gregory XIII introduced the new calendar in the 16th century, new year's day was the Feast of the Circumcision of Christ, and that's the way the calendar was until the liturgical reforms of the Second Vatican Ecumenical Council restored the Solemnity of Mary, Mother of God to the 1st, which is when it had been celebrated in ancient times since the early councils established the dogma of Theotokos.
So, I think I'd rather say I celebrate the New-Fangled Gregorian January 1st.