The First Saturdays Devotion (also called the Act of Reparation to the Immaculate Heart of Blessed Virgin Mary) is a Catholic devotion which, according to Lúcia of Fátima, was requested by the Virgin Mary in an apparition at Pontevedra, Spain in December 1925. This devotion has been approved by the Roman Catholic Church.
The pious practice of honoring the Blessed Mother on Saturday is an ancient custom largely attributed to the Benedictine monk Alcuin (735-804), "Minister of Education" at the court of Charlemagne, composed a Votive mass formulary for each day of the week. Alcuin assigned two formularies to Saturday in honor of Our Lady. The practice was quickly embraced by both clergy and laity.
The First Saturdays devotion had already been an established custom in the Catholic Church. On July 1, 1905, Pope Pius X approved and granted indulgences for the practice of the First Saturdays of twelve consecutive months in honor of the Immaculate Conception. This practice greatly resembled the reported request of Mary at the Pontevedra apparitions.
At the age of 14, Lúcia Santos, one of the purported visionaries of Our Lady of Fátima was admitted as a boarder to the school of the Sisters of St. Dorothy in Vilar, near the city of Porto. On October 24, 1925, she entered the Institute of the Sisters of St. Dorothy as a postulant in the convent in Tui, Spain, just across the northern Portuguese border.
Sister Lucia later reported that on December 10,1925, the Virgin Mary appeared to her at the convent in Pontevedra, Spain, and by Her side, elevated on a luminous cloud, was the Child Jesus. According to Lucia, Mary requested the institution of the Devotion of the Five First Saturdays in reparation to her Immaculate Heart.