A Day of Penance and Prayer

From the U.S. Conference of Catholic Bishops:

In November, 2001, the United States Conference of Catholic Bishops approved the adaptation of the General Instruction of the Roman Missal. Following confirmation by the Holy See in February, 2002, the following became particular law for the dioceses of the United States of America:

In all the dioceses of the United States of America, January 22 (or January 23, when the 22nd falls on a Sunday) shall be observed as a particular day of penance for violations to the dignity of the human person committed through acts of abortion, and of prayer for the full restoration of the legal guarantee of the right to life. The Mass "For Peace and Justice" (no. 21 from "Masses for Various Needs") should be celebrated with violet vestments as an appropriate liturgical observance for this day.

On January 22, a "day of penance for violations to the dignity of the human person committed through acts of abortion, and of prayer for the full restoration of the legal guarantee of the right to life" will be mandatory in the dioceses of the U.S. for the first time. As an "Optional Memorial," the Mass celebrated that day may be the Mass "For Peace and Justice" or follow the normal weekday Mass readings and prayers for the day found in the Ordo, with or without optional prayers related to St. Vincent of Saragossa whose Feast Day falls on January 22.

(emphasis added)