Feast Days of Mary, Queen of the Apostles are holy days celebrated by Christians in a Church year. These days are celebrated in reverence to Mary, mother of Jesus. The number and in some cases dates of Marian Feasts vary in different Christian denominations.
12 days
A feast which commemorates the Descent of the Holy Ghost upon the Apostles, fifty days after the Resurrection of Christ.
There are three for Sundays and solemn feast days- one from the Old Testament, one from the writings of the apostles, and one from the Gospel. The Second Reading (From the writings of the apostles) is left out on Weekday Masses.
Because it is part of the 12 days of Christmas.
It was written by the 12 apostles
The Feast of the Epiphany - the feast celebrating the arrival of the three magi to the Christ Child. http://en.wikipedia.org/wiki/Epiphany_(holiday)
12 apostles
Jesus himself found and selected the 12 apostles.
The most important feast days are called Holy Days of Obligation.
Jesus had 12 apostles.
For a complete list of the feast days of saints click here.