But to remember the sublime memorial to the Immaculate Heart of Mary, read on:
In the midst of the second world war Pope Pius XII put the whole world under the special protection of our Savior's Mother by consecrating it to her Immaculate Heart, and in 1944 he decreed that in the future the whole Church should celebrate the feast of the Immaculate Heart of Mary. This is not a new devotion. In the seventeenth century, St. John Eudes preached it together with that of the Sacred Heart; in the nineteenth century, Pius VII and Pius IX allowed several churches to celebrate a feast of the Pure Heart of Mary. Pius XII instituted today's feast of the Immaculate Heart of Mary for the whole Church, so as to obtain by her intercession "peace among nations, freedom for the Church, the conversion of sinners, the love of purity and the practice of virtue" (Decree of May 4, 1944). In 1942 during the ravages of World War II, Pope Pius XII dedicated the world to the Immaculate Heart of Mary and set the feast for August 22nd. In 1969, Pope Paul VI moved the celebration of the Immaculate Heart of Mary to the day, Saturday, immediately after the Solemnity of the Sacred Heart of Jesus.