Question: On what date was the author of the Sacerdotalis Caelibatus born?

full_context: Document 1: Pope Paul VI: Pope Paul VI (Latin: Paulus VI; Italian: Paolo VI), born Giovanni Battista Enrico Antonio Maria Montini (Italian pronunciation: [dʒioˈvani baˈtista enˈriko anˈtonjo marˈija monˈtini]; 26 September 1897 – 6 August 1978), reigned as Pope from 21 June 1963 to his death in 1978. Succeeding Pope John XXIII, he continued the Second Vatican Council which he closed in 1965, implementing its numerous reforms, and fostered improved ecumenical relations with Eastern Orthodox and Protestants, which resulted in many historic meetings and agreements. Montini served in the Vatican's Secretariat of State from 1922 to 1954. While in the Secretariat of State, Montini and Domenico Tardini were considered as the closest and most influential colleagues of Pope Pius XII, who in 1954 named him Archbishop of Milan, the largest Italian diocese. Montini automatically became the Secretary of the Italian Bishops Conference. John XXIII elevated him to the College of Cardinals in 1958, and after the death of John XXIII, Montini was considered one of his most likely successors.
Document 2: Pope Paul VI: Sacerdotalis caelibatus (Latin for "Of the celibate priesthood"), promulgated on 24 June 1967, defends the Catholic Church's tradition of priestly celibacy in the West. This encyclical was written in the wake of Vatican II, when the Catholic Church was questioning and revising many long-held practices. Priestly celibacy is considered a discipline rather than dogma, and some had expected that it might be relaxed. In response to these questions, the Pope reaffirms the discipline as a long-held practice with special importance in the Catholic Church. The encyclical Sacerdotalis caelibatus from 24 June 1967, confirms the traditional Church teaching, that celibacy is an ideal state and continues to be mandatory for Roman Catholic priests. Celibacy symbolizes the reality of the kingdom of God amid modern society. The priestly celibacy is closely linked to the sacramental priesthood. However, during his pontificate Paul VI was considered generous in permitting bishops to grant laicization of priests who wanted to leave the sacerdotal state, a position which was drastically reversed by John Paul II in 1980 and cemented in the 1983 Canon Law that only the pope can in exceptional circumstances grant laicization.
Document 3: Casti connubii: Casti connubii (Latin: "of chaste wedlock") was a papal encyclical promulgated by Pope Pius XI on 31 December 1930 in response to the Lambeth Conference of the Anglican church. It stressed the sanctity of marriage, prohibited Catholics from using any form of artificial birth control, and reaffirmed the prohibition on abortion. It also explained the authority of Church doctrine on moral matters, and advocated that civil governments follow the lead of the Church in this area.
Document 4: Pope Paul VI: Of his eight encyclicals, Pope Paul VI is best known for his encyclical Humanae vitae (Of Human Life, subtitled On the Regulation of Birth), published on 25 July 1968. In this encyclical he reaffirmed the Catholic Church's traditional view of marriage and marital relations and a continued condemnation of artificial birth control. There were two Papal committees and numerous independent experts looking into the latest advancement of science and medicine on the question of artificial birth control. which were noted by the Pope in his encyclical The expressed views of Paul VI reflected the teachings of his predecessors, especially Pius XI, Pius XII and John XXIII and never changed, as he repeatedly stated them in the first few years of his Pontificate
Document 5: Pope John XXIII: The Roman Catholic Church celebrates his feast day not on the date of his death, June 3, as is usual, nor even on the day of his papal inauguration (as is sometimes done with Popes who are Saints, such as with John Paul II) but on 11 October, the day of the first session of the Second Vatican Council. This is understandable, since he was the one who had had the idea for it and had convened it. On Thursday, 11 September 2014, Pope Francis added his optional memorial to the worldwide General Roman Calendar of saints' feast days, in response to global requests. He is commemorated on the date of his death, 3 June, by the Evangelical Lutheran Church in America and on the following day, 4 June, by the Anglican Church of Canada and the Episcopal Church (United States).
Document 6: Sacerdotalis caelibatus: Sacerdotalis caelibatus (Latin for "Of priestly celibacy") is an encyclical written by Pope Paul VI. It defends the Catholic Church's tradition of clerical celibacy in the West. The encyclical was dated 24 June 1967.
Document 7: Pope John XXIII: The 50th anniversary of his death was celebrated on 3 June 2013 by Pope Francis, who visited his tomb and prayed there, then addressing the gathered crowd and spoke about the late pope. The people that gathered there at the tomb were from Bergamo, the province where the late pope came from. A month later, on 5 July 2013, Francis approved Pope John XXIII for canonization, along with Pope John Paul II without the traditional second miracle required. Instead, Francis based this decision on John XXIII's merits for the Second Vatican Council. On Sunday, 27 April 2014, John XXIII and Pope John Paul II were declared saints on Divine Mercy Sunday.
Document 8: Pope Paul VI: Paul VI revolutionized papal elections by ordering that only cardinals below the age of eighty might participate in future conclaves. In Ecclesiae Sanctae, his motu proprio of 6 August 1966, he further invited all bishops to offer their retirement to the pontiff no later than the completion of their 75th year of age. This requirement was extended to all Cardinals of the Catholic Church on 21 November 1970. With these two stipulations, the Pope filled several positions with younger bishops and cardinals, and further internationalized the Roman Curia in light of several resignations due to age.
Document 9: Pope Paul VI: Pius XII delivered an address about Montini's appointment from his sick-bed over radio to those assembled in St. Peter's Basilica on 12 December 1954. Both Montini and the pope had tears in their eyes when Montini parted for his dioceses with 1,000 churches, 2,500 priests and 3,500,000 souls. On 5 January 1955, Montini formally took possession of his Cathedral of Milan. Montini, after a period of preparation, liked his new tasks as archbishop, connecting to all groups of faithful in Milan. He enjoyed meetings with intellectuals, artists and writers.
Document 10: Pope Paul VI: In December 2013, Vatican officials approved a supposed miracle that was attributed to the intercession of the late pontiff which was the curing of an unborn child in California, U.S.A in the 1990s. It was expected that Pope Francis would approve the miracle in the near future, thus, warranting the beatification of the late pontiff. In February 2014, it was reported that the consulting Vatican theologians to the Congregation for the Causes of Saints recognized the miracle attributed to the late pontiff.
Document 11: Pope Paul VI: On 24 April 2014, it was reported in the Italian magazine Credere that the late pope could possibly be beatified on 19 October 2014. This report from the magazine further stated that several cardinals and bishops would meet on 5 May to confirm the miracle that had previously been approved, and then present it to Pope Francis who may sign the decree for beatification shortly after that. The Congregation for the Causes of Saints held that meeting and positively concluded that the healing was indeed a miracle that could be attributed to the late pope. The matter shall now soon be presented to the pope for approval.
Document 12: Pope Paul VI: On 20 December 2012, Pope Benedict XVI, in an audience with the Cardinal Prefect of the Congregation for the Causes of Saints, declared that the late pontiff had lived a life of heroic virtue, which means that he could be called "Venerable". A miracle attributed to the intercession of Paul VI was approved on 9 May 2014 by Pope Francis. The beatification ceremony for Paul VI was held on 19 October 2014, which means that he can now be called "Blessed". His liturgical feast day is celebrated on the date of his birth, 26 September, rather than the day of his death as is usual.
Document 13: Pope Paul VI: Paul VI supported the new-found harmony and cooperation with Protestants on so many levels. When Cardinal Augustin Bea went to see him for permission for a joint Catholic-Protestant translation of the Bible with Protestant Bible societies, the pope walked towards him and exclaimed, "as far as the cooperation with Bible societies is concerned, I am totally in favour." He issued a formal approval on Pentecost 1967, the feast on which the Holy Spirit descended on the Christians, overcoming all linguistic difficulties, according to Christian tradition.
Document 14: Pope Paul VI: Ecclesiam suam was given at St. Peter's, Rome, on the Feast of the Transfiguration, 6 August 1964, the second year of his Pontificate. It is considered an important document, identifying the Catholic Church with the Body of Christ. A later Council document Lumen Gentium stated that the Church subsists in the Body of Christ, raising questions as to the difference between "is" and "subsists in". Paul VI appealed to "all people of good will" and discussed necessary dialogues within the Church and between the Churches and with atheism.
Document 15: Pope Paul VI: In 1916, he entered the seminary to become a Roman Catholic priest. He was ordained priest on 29 May 1920 in Brescia and celebrated his first Holy Mass in Brescia in the Basilica of Santa Maria delle Grazie. Montini concluded his studies in Milan with a doctorate in Canon Law in the same year. Afterwards he studied at the Gregorian University, the University of Rome La Sapienza and, at the request of Giuseppe Pizzardo at the Accademia dei Nobili Ecclesiastici. At the age of twenty-five, again at the request of Giuseppe Pizzardo, Montini entered the Secretariat of State in 1922, where he worked under Pizzardo together with Francesco Borgongini-Duca, Alfredo Ottaviani, Carlo Grano, Domenico Tardini and Francis Spellman. Consequently, he spent not a day as a parish priest. In 1925 he helped found the publishing house Morcelliana in Brescia, focused on promoting a 'Christian inspired culture'.
ground_truth: 26 September
sub_queries: Sacerdotalis Caelibatus >> author Answer: Paul VI
On what day was Paul VI born? Answer: 26 September