 In Zen Buddhism retreats are known as sesshin.The Christian retreat can be defined most simply as a definite time (from a few hours in length to a month) spent away from one's normal life for the purpose of reconnecting, usually in prayer, with God.Although the practice of leaving one's everyday life to connect on a deeper level with God, be that in the desert (as with the Desert Fathers), or in a monastery, is as old as Christianity itself, the practice of spending a specific time away with God is a more modern phenomenon, dating from the 1520s and St. Ignatius of Loyola's composition of the Spiritual Exercises.