Saint Michael and All Angels, often called Michaelmas, is a feast day celebrating the archangel Michael and the heavenly host of angels. In Christian tradition, Michael is revered as the protector of God's people and the leader of the heavenly armies who triumphed over evil, as described in the Book of Revelation. The day honors all the angels for their roles as messengers, guardians, and servants of God who minister to humanity. Its feast day is celebrated annually on September 29.