Answer by taking a quote from the following article:

Saint Pedro Calungsod (Latin: Petrus Calungsod, Spanish: Pedro Calungsod or archaically Pedro Calonsor, Italian: Pietro Calungsod; July 21, 1654 - April 2, 1672), also known as Peter Calungsod and Pedro Calonsor, was a Roman Catholic Filipino migrant, sacristan and missionary catechist who, along with the Spanish Jesuit missionary Diego Luis de San Vitores, suffered religious persecution and martyrdom in Guam for their missionary work in 1672. While in Guam, Calungsod preached Christianity to the Chamorro people through catechism, while baptizing infants, children and adults at the risk and expense of being persecuted and eventually murdered.

On December 19, 2011, the Holy See officially approved the miracle qualifying Calungsod for sainthood by the Roman Catholic Church. The recognized miracle dates from March 26, 2003, when a woman from Leyte who was pronounced clinically dead by accredited physicians two hours after a heart attack was revived when an attending physician invoked Calungsod's intercession.  Cardinal Angelo Amato presided over the declaration ceremony on behalf of the Congregation for the Causes of Saints. He later revealed that Pope Benedict XVI approved and signed the official promulgation decrees recognising the miracles as authentic and worthy of belief. The College of Cardinals were then sent a dossier on the new saints, and they were asked to indicate their approval. On February 18, 2012, after the Consistory for the Creation of Cardinals, Cardinal Amato formally petitioned Pope Benedict XVI to announce the canonization of the new saints. The Pope set the date for the canonization ceremony to October 21, 2012 on World Mission Sunday, 340 years after Calungsod's death.  On October 21, 2012, Pope Benedict XVI canonised Calungsod in Saint Peter's Square. The pope donned a pearl-studded mitre preciosa and a cream-colored, pleated Papal fanon, a special vestment reserved only for the pontiff and used on the most solemn and rare liturgical occasions. Filipino Cardinal Ricardo Jamin Vidal concelebrated at the canonization Mass, and of note is that amongst the seven new saints, Calungsod was the only one without a first class relic exposed for veneration since his body was thrown into the sea. The cutlass knife used to hack Calungsod's head and neck was retrieved by Cardinal Vidal from Guam, and is currently venerated as a second-class relic. During the homily, Benedict XVI maintained that Calungsod received the Sacrament of Absolution from Diego Luis de San Vitores before his martyrdom and death.  After Saint Lorenzo Ruiz of Manila, Calungsod is the second Filipino to be declared a saint by the Roman Catholic Church. The Roman Martyrology celebrates Calungsod's feast along with Blessed Diego Luis de San Vitores every April 2, their dies natalis (heavenly birthdate). However, whenever April 2 falls within Holy Week or within the Octave of Easter, his feast is celebrated on the Saturday of the Fifth Week of Lent, that is, the Saturday before Palm Sunday.  Saturday has been designated as the day of devotion and novenas in his honour.

On what day of the week is sainthood shared?