Saint Benedict
Pietro Perugino, ca. 1495

As the Prophet saith: "Seven times a day I have given praise to Thee," this sacred sevenfold number will be fulfilled by us in this wise if we perform the duties of our service at the time of Lauds, Prime, Tierce, Sext, None, Vespers, and Compline; because it was of these day hours that he hath said: "Seven times a day I have given praise to Thee." For the same Prophet saith of the night watches: "At midnight I arose to confess to Thee." At these times, therefore, let us offer praise to our Creator "for the judgments of His justice;" namely, at Lauds, Prime, Tierce, Sext, None, Vespers, and Compline; and let us rise at night to praise Him.
-The Rule of St. Benedict, XVI