Originally, September 29 was the Feast of the Dedication of the Basilica of St. Michael at Monte Gargano. The other two archangels had their own feast day celebrations. In the new liturgical calendar published in 1969, all three archangels were grouped together on September 29 as a way to simplify the calendar. Michael the Archangel is named in the Book of Daniel, the Letter of St. Jude,...