Analysis of information sources in references of the Wikipedia article "Twelve Days of Christmas" in English language version.
This arrangement became an administrative problem for the Roman Empire as it tried to coordinate the solar Julian calendar with the lunar calendars of its provinces in the east. While the Romans could roughly match the months in the two systems, the four cardinal points of the solar year--the two equinoxes and solstices--still fell on different dates. By the time of the first century, the calendar date of the winter solstice in Egypt and Palestine was eleven to twelve days later than the date in Rome. As a result the Incarnation came to be celebrated on different days in different parts of the Empire. The Western Church, in its desire to be universal, eventually took them both--one became Christmas, one Epiphany--with a resulting twelve days in between. Over time this hiatus became invested with specific Christian meaning. The Church gradually filled these days with saints, some connected to the birth narratives in Gospels (Holy Innocents' Day, December 28, in honor of the infants slaughtered by Herod; St. John the Evangelist, "the Beloved," December 27; St. Stephen, the first Christian martyr, December 26; the Holy Family, December 31; the Virgin Mary, January 1). In 567, the Council of Tours declared the twelve days between Christmas and Epiphany to become one unified festal cycle.
In 567 AD, the Council of Tours ended a dispute. Western Europe celebrated Christmas, 25 December, as the holiest day of the season... but Eastern Europe celebrated Epiphany, 6 January, recalling the Wise Men's visit and Jesus' baptism. It could not be decided which day was holier, so the Council made all 12 days from 25 December to 6 January "holy days" or "holidays," These became known as "The Twelve Days of Christmas."
Christmas is a major holiday for Christians, although some non-Christians in the United States also mark the day as a holiday.
De Decembri usque ad natale Domini, omni die ieiunent. Et quia inter natale Domini et epiphania omni die festivitates sunt, itemque prandebunt. Excipitur triduum illud, quo ad calcandam gentilium consuetudinem, patres nostri statuerunt privatas in Kalendariis Ianuarii fieri litanias, ut in ecclesiis psallatur, et hora octava in ipsis Kalendis Circumcisionis missa Deo propitio celebretur. (Translation: "In December until Christmas, they are to fast each day. Since between Christmas and Epiphany there are feasts on each day, they shall have a full meal, except during the three-day period on which, in order to tread Gentile customs down, our fathers established that private litanies for the Calends of January be chanted in the churches, and that on the Calends itself Mass of the Circumcision be celebrated at the eighth hour for God's favour.")
The Council of Tours (567) proclaimed the twelve days from Christmas to Epiphany as a sacred and festive season, and established the duty of Advent fasting in preparation for the feast. The Council of Braga (563) forbade fasting on Christmas Day.
The Twelve Days of Christmas ... in most of the Western Church are the twelve days from Christmas until the beginning of Epiphany (January 6th; the 12 days count from December 25th until January 5th). In some traditions, the first day of Christmas begins on the evening of December 25th with the following day considered the First Day of Christmas (December 26th). In these traditions, the twelve days begin December 26[th] and include Epiphany on January 6[th].
On the Twelve Days of Christmas Alleluia. Unto us a child is born: O come, let us adore Him. Alleluia.
The Council of Tours (567) decreed the 12 days from Christmas to Epiphany to be sacred and especially joyous, thus setting the stage for the celebration of the Lord's birth...
Western Europe celebrated Christmas December 25 as the holiest day. Eastern Europe celebrated January 6 the Epiphany, the visit of the Wise Men, as the holiest day... and so they had this council and they decided to make all twelve days from December 25 to January 6 the Twelve Days of Christmas.
In the year 567 the church council of Tours called the 13 days between December 25 and January 6 a festival season.
The Second Council of Tours (can. xi, xvii) proclaims, in 566 or 567, the sanctity of the "twelve days" from Christmas to Epiphany, and the duty of Advent fast; ...and that of Braga (563) forbids fasting on Christmas Day. Popular merry-making, however, so increased that the "Laws of King Cnut", fabricated c. 1110, order a fast from Christmas to Epiphany.
Around the year 400 the feasts of St Stephen, John the Evangelist and the Holy Innocents were added on succeeding days, and in 567 the Council of Tours ratified the enduring 12-day cycle between the nativity and the epiphany.
Western Europe celebrated Christmas December 25 as the holiest day. Eastern Europe celebrated January 6 the Epiphany, the visit of the Wise Men, as the holiest day... and so they had this council and they decided to make all twelve days from December 25 to January 6 the Twelve Days of Christmas.
{{cite book}}: CS1 maint: location missing publisher (link){{cite book}}: CS1 maint: location missing publisher (link)