The Church celebrates the Holy Name of Mary on September 12. The feast was placed in the octave of the Nativity of the Virgin Mary to remind Christians that they can have recourse to the intercession of the Virgin Mary in times of trial, great or small, as we learn in the story of the Wedding at Cana and by the words of Christ on the Cross : "Behold your Mother."
The feast of the Holy Name of Mary was dropped from the new liturgical calendar in 1970, due to progress in historical studies and in an effort to reduce the number of devotional feasts to raise the profile of major Marian feasts, especially those associated with the life of Our Lord following the Second Vatican Council. But because this feast did commemorate a significant Marian event, it was reinstated on March 22, 2002, by Pope Saint John Paul II. Since the 2001 terrorist attacks and the January 2002 Day of Prayer for Peace in Assisi, the date is now given in the third edition of the Roman Missal and in the Roman Martyrology.
The spiritual reason to restore this feast was that the saints have, traditionally, always invoked the name of Mary. For example, Saint Bernard famously said: "Look at the Star!", pointing to Mary as a refuge in times of trial.
The historical reason is directly related to the history Poland, John Paul II’s homeland, and the fate of Europe: the liberation of Vienna from the Ottomans was the deed of Polish King Jan Sobieski, on September 11, 1683. This victory is depicted in the frescoes of the "Polish Chapel" of the Basilica of Loreto, Italy (the Santa Casa or "Holy House"). Pope Innocent XI attributed this very important victory to the intercession of the Virgin Mary and instituted the feast of the Holy Name of Mary to commemorate it.
Two months after that victory - on November 25, 1683 - the feast of the Holy Name of Mary was instituted for the universal Church. A week later, on the following Sunday, the Nativity of Mary was celebrated. Later, Pope St. Pius X moved the Holy Name of Mary to September 12, to commemorate the first Thanksgiving Mass said on the day after the victory. But John Paul II thought it important to bring it back to its original date, as a reminder to Catholics to always invoke Mary when faced with dangers of historical proportion.