The Feast of Fools (Latin: "festum fatuorum, festum stultorum" ) is the name given to a specific feast day celebrated by the clergy in Europe, initially in Northern France, but later more widely.
 Its later reception history has considerably obscured modern understandings of the nature and meaning of this celebration, which originated in proper liturgical observance, and has more to do with other examples of medieval liturgical drama than with either the earlier pagan (Roman) feasts of Saturnalia and Kalends or the later bourgeois lay sotie.
Saint Lucy's Day, also called the Feast of Saint Lucy, is a Christian feast day celebrated on 13 December in Advent, commemorating Saint Lucy, a 3rd-century martyr under the Diocletianic Persecution, who according to legend brought "food and aid to Christians hiding in the catacombs" using a candle-lit wreath to "light her way and leave her hands free to carry as much food as possible".
 Her feast once coincided with the Winter Solstice, the shortest day of the year before calendar reforms, so her feast day has become a Christian festival of light.
 Falling within the Advent season, Saint Lucy's Day is viewed as an event signaling the arrival of Christmastide, pointing to the arrival of the Light of Christ in the calendar, on Christmas Day.
Samfundet Folkhälsan, or in short Folkhälsan (literally "Public Health"), is a non-governmental organization based in Finland.
 It is active in advocating social welfare and health care for the Swedish speakers of Finland.
 The organization carries out scientific research and informs and counsels in order to promote health and good quality of life.
 The organization also runs a multicultural international children's home in Oulunkylä and is organizing the annual national Saint Lucy's Day celebrations in Finland.
Protasius (Italian: "Protaso" ) was Archbishop of Milan.
 He is honored as a saint in the Catholic Church, with his feast day celebrated on 24 November, the day of his death.
The Visitation is the visit of Mary with Elizabeth as recorded in the Gospel of Luke, .
 It is also the name of a Christian feast day commemorating this visit, celebrated on 31 May in the West (2 July in calendars of the 1263–1969 period, and in the modern regional calendar of Germany) and Hungary and 30 March among Eastern Christians.
Saint Joseph's Day, March 19, the Feast of Saint Joseph is in Western Christianity the principal feast day of Saint Joseph, husband of the Blessed Virgin Mary.
 He is the foster-father of Jesus Christ.
 It has the rank of a solemnity in the Roman Catholic Church.
 It is a feast or commemoration in the provinces of the Anglican Communion, and a feast or festival in the Lutheran Church.
 Saint Joseph's Day is the Patronal Feast day for Poland as well as for Canada, persons named Joseph, Josephine, etc., for religious institutes, schools and parishes bearing his name, and for carpenters.
 It is also Father's Day in some Catholic countries, mainly Spain, Portugal, and Italy.
 It is a holiday of obligation for Roman Catholics, unless the particular Episcopal Conference has waived the obligation.
Pope Leo IX (21 June 1002 – 19 April 1054), born Bruno of Egisheim-Dagsburg, was Pope from 12 February 1049 to his death in 1054.
 He was a German aristocrat and a powerful ruler of central Italy while holding the papacy.
 He is regarded as a saint by the Roman Catholic Church, his feast day celebrated on 19 April.
Saint Dominic in Soriano (Italian: "San Domenico in Soriano" ; Spanish: "Santo Domingo en Soriano" ) refers to a portrait of Saint Dominic which was from 1530 an important artefact in the Dominican friary at Soriano Calabro in southern Italy.
 It was believed to be of miraculous origin, and to be capable of working miracles.
 It was the subject of a Roman Catholic feast day celebrated on 15 September from 1644 to 1912.
 Its miraculous origin was the subject of several 17th-century paintings.
 Several ecclesiastical buildings have been named after it.
 It may no longer exist.
Epiphany ( ), also Theophany or Three Kings' Day, is a Christian feast day that celebrates the revelation of God incarnate as Jesus Christ.
 In Western Christianity, the feast commemorates principally (but not solely) the visit of the Magi to the Christ child, and thus Jesus' physical manifestation to the Gentiles. Moreover, the feast of the Epiphany, in some Western Christian denominations, also initiates the liturgical season of Epiphanytide.
 Eastern Christians, on the other hand, commemorate the baptism of Jesus on both sides of the Jordan River, seen as his manifestation to the world as the Son of God.
 Qasr el Yahud in the West Bank, and Al-Maghtas in Jordan on the east bank, Al-Maghtas is considered to be the original site of the baptism of Jesus and the ministry of John the Baptist.
Allhallows' Day, or All Saints' Day, a Christian feast day

Question: Which organization runs the Christian feast day celebrated on 13 December in Advent?
Answer: Samfundet Folkhälsan