The Feast of St. Michael, Archangel is celebrated each year on the 29th day of September.  Scripture records Michael, whose name means “Who is like unto God” in Hebrew, is referred to in a heavenly, perhaps theophanic vision, as one of the “chief princes”, who engages in heavenly combat to aid in victory for God’s elect (Daniel 10:13- 21 and 12:1).  It is Michael who contends with the devil, disputing over the body of Moses, not speaking a reviling word against him but simply saying “The Lord rebuke you!” (Jude 5, 9).   It is ”Michael and his angels” who prevail over the dragon and his angels in the great heavenly war, casting the devil and his angels down to earth. (Revelation 12:7-9) 

In addition to Holy Scripture, several apocryphal books mention Michael (Assumption of Moses, Enoch, and Ascension of Isaiah).  Because of these passages, Michael has been regarded as the Archangel that fights for Christians against heathens, and protects Christians against the assaults of the devil.  In old Roman Catholicism Michael was held to be the angel that bears Christian souls to God at the time of death.  

Michael is named in the Leonine (Veronense, 5th century) sacramentary, the most ancient of all surviving manuscripts of the Western rite.  There Michael is named in Masses celebrated on September 30 commemorating the dedication of a basilica bearing his name, six miles north of ancient Rome on the Via Salaria.  Western tradition records a vision of St. Michael on the mountain Garganus in south eastern Italy in the 5th century. 

The Feast of St. Michael, Archangel, was historically celebrated without the inclusion of “all holy angels”, apparently an addition of the Book of Common Prayer.  Since the 1600s the “first free day” after the Feast of St. Michael, Archangel, October 2nd, was observed as the Feast of the Holy Guardian Angels.  St. Raphael, the “healing angel”, who appears outside of Scripture in Tobit and 1 Enoch, was historically commemorated on October 24th.  The Archangel Gabriel was historically commemorated on March 24th. 

A skip in the liturgical calendar occurs after the Feast of St. Michael, Archangel. The time after September 29, through the week before the Third-Last Sunday of the Church Year, is known as Michaeltide.  The Sunday following September 29 is the First Sunday after Michaelmass, for which the Propers for Trinity XIX are used, after which the Sundays are counted consecutively until the Third-Last Sunday.

Information in this post is drawn from “Michael the Archangel, St.” in The Oxford Dictionary of the Christian Church, 3rd ed.  F.L. Cross and E.A. Livingstone, eds.  [Oxford: Oxford University Press, 1997], 1082; The St. Andrew Daily Missal, [St. Bonaventure Pulications: Great Falls, Montana, 1999], 1471-1478, 1479-1482; The New Westminster Dictionary of Liturgy & Worship, ed. Paul Bradshaw [2002, Louisville: John Knox Press]; and several other sources.