11 And so during the month of October, dedicated to Our Lady of the Rosary, prayers and petitions should be increased, so that through her intercession the dawn of true peace may shine forth to men. This means true religious peace too, for unfortunately, not everyone is allowed to profess his religion freely in this age. In particular, We want October 4th—the day on which, as We mentioned earlier, We went last year to the United Nations for the sake of peace—to be celebrated throughout the whole Catholic world this year as a Day of Prayer for Peace. It will be up to you, venerable brethren, in the light of your own commendable devotion and on the basis of the obvious importance of this matter, to prescribe sacred ceremonies in which priests, religious and the faithful—especially boys and girls in the flower of their innocence, and the sick and others who are suffering—can all ask the help of the Mother of God and of the Church.
Source: Christi Matri (Vatican.va)