Our Lady of Fatima is a fairly new feast compared with Our Lady of the Most Blessed Sacrament. Both can be celebrated on May 13. Our priest at Mass today, talked about Our Lady of the Blessed Sacrament more than Our Lady of Fatima.
History of the Title of Our Lady of the Most Blessed Sacrament
Feast Day, May 13
St. Peter Julian Eymard, of France, had a strong devotion to the Holy Eucharist and Our Lady and began his priestly life in the Society of Mary. “But his heart burned with the desire to establish perpetual adoration of Jesus in the Blessed Sacrament exposed upon a royal throne and surrounded by a large court of adorers. On February 2, 1851, at the shrine of Fourvière, the most Blessed Virgin had made him understand its necessity. ‘All the mysteries of my Son have a religious order of men to honor them. The Eucharist alone has none . . . .’ After several years of prudent reflection and interior combat, encouraged by Pope Pius IX, he founded the Congregation of the Most Blessed Sacrament at Paris on May 13, 1856” (St. Peter Julian Eymard: Apostle of the Eucharist Novena, p. 20).
The title of Our Lady of the Blessed Sacrament was first given to Mary by St. Peter Julian Eymard in May 1868, while speaking to his novices. A few years later he described what her statue should look like: "The Blessed Virgin holds the Infant in her arms; and He holds a chalice in one hand and a Host in the other." He exhorted them to invoke Mary: "Our Lady of the Blessed Sacrament, pray for us who have recourse to thee!"
Later, Pius IX enriched the invocation with indulgences. Twice, St. Pius X did the same. On December 30, 1905, he granted a 300 days indulgence to the faithful who pray: “Our Lady of the Most Blessed Sacrament, pray for us.”
"This title, Our Lady of the Blessed Sacrament, is perhaps the most meaningful of all," said St. Pius X.
In 1921 the Sacred Congregation of Rite authorized the Blessed Sacrament Congregations to celebrate each year, on the 13th of May, a "solemn commemoration of the Blessed Virgin," with the intention of honoring Mary under the title of "Our Lady of the Most Blessed Sacrament." And of course this Feast is still celebrated today with great joy by all the spiritual sons and daughters of St. Peter Julian Eymard.
Pope Bl. John XXIII codified the title of Our Lady of the Most Blessed Sacrament when he declared St. Peter Julian Eymard a saint on December 9, 1962, at the end of the last session of the Second Vatican Council.