Do we have to go to Mass on January 1?

This year, in the United States, no.

The USCCB notes on its liturgical calendar:

Since the Solemnity of Mary, the Holy Mother of God on January 1, 2018 falls on a Monday this year, it is not observed as a Holy Day of Obligation.

Catholic Answers explains:

In accord with the provisions of canon 1246 §2 of the Code of Canon Law, the USCCB has ruled: “Whenever January 1, the solemnity of Mary, Mother of God, or August 15, the solemnity of the Assumption, or November 1, the solemnity of All Saints, falls on a Saturday or on a Monday, the precept to attend Mass is abrogated” (www.usccb.org). This covers the bulk of instances in which you will find holy days of obligation dispensed for Latin-rite Catholics in the United States. However, there is one more provision of canon law to keep in mind: “Whenever he judges that it contributes to their spiritual welfare, the diocesan bishop can dispense the faithful from disciplinary laws, both universal laws and those particular laws made by the supreme ecclesiastical authority, for his territory or his subjects” (CIC 87 §1). This means that an individual bishop can dispense the obligation of a holy day of obligation for his diocese. That is why in some U.S. dioceses January 1 is celebrated as a holy day of obligation, and in others it is not.

Nonetheless, in Canada (and, I presume, other places, as well), it is a holy day of obligation.

Confused? Yeah. Me, too. It’s unclear why this has to be the case. But if you’re looking for a great start for the new year, I can’t think of a better way than by attending holy Mass. The responsorial psalm alone offers us an opportunity to recite this great prayer of trusting hope:

R. (2a) May God bless us in his mercy. May God have pity on us and bless us; may he let his face shine upon us. So may your way be known upon earth; among all nations, your salvation. R. May God bless us in his mercy. May the nations be glad and exult because you rule the peoples in equity; the nations on the earth you guide.

A happy and blessed 2018, one and all!