Christian spirituality has always unfolded within the fabric of time, yet it has never regarded time as a neutral container in which sacred things merely happen. From the earliest pages of Scripture to the refined liturgical and monastic systems of the Middle Ages, time appears as a divine gift, a pedagogical medium, and the very arena in which salvation is worked out. The Christian tradition does not treat time as a passive backdrop but as a dynamic reality shaped by God's creative act, wounded by sin, redeemed in Christ, and destined for transfiguration at the end of history. This book explores how monastic and medieval Christianity received, interpreted, and sanctified time, crafting a spiritual architecture in which the hours of the day, the seasons of the year, and the stages of life became pathways toward union with God.