 As this feast celebrates the Incarnation of the Second Person of the Trinity, many Church Fathers, including St. Athanasius, St. Gregory of Nyssa, and St. Augustine, have expounded on it.From the earliest recorded history, the feast has been celebrated on March 25, commemorating both the belief that the spring equinox was not only the day of God's act of Creation but also the beginning of Christ's redemption of that same Creation.All Christian antiquity held 25 March as the actual day of Jesus' death.