Catholic Encyclopedia (1913)/Liturgical Week
The week as a measure of time is a sufficiently obvious division of the lunar month, and the discussion carried on with much learning as to whether this seven days' period is ultimately of Babylonian origin has no great importance. In any case the week was regarded as a sacred institution among the Jews owing to the law of the Sabbath rest and its association with the first chapter of Genesis. The earliest Christian converts were no doubt tenacious of the usages (so far as they were compatible with the law of the Gospel) in which they had been brought up. The Sunday, "the first day of the week" (Acts, xx, 7; I Cor., xvi, 2; cf. Apoc., i, 10), soon replaced the Sabbath as the great day of religious observance, but the week itself remained as before. Indeed, there is much to recommend the idea that in the first and second centuries the only commemorations of the great Christian mysteries formed a weekly, not an annual, cycle. Sunday, according to the Epistle of Barnabas (xv), was "the beginning of another world", and the writer further says: "Wherefore also we keep the eighth day for rejoicing, in the which also Jesus rose from the dead and having been manifested ascended into the heavens". Again the Didache (viii) ordains: "Let not your fasts be with the hypocrites; for they fast on the second and fifth days of the week, but do ye fast on the foruth and on the Friday", while in c. xiv we are told "And on the Lord's day of the Lord come together and break bread and give thanks". Altogether it becomes clear from the language of Tertullian, the Apostolic Constitution, and other early writers that the Sunday in each week was regarded as commemorating the Resurrection, and the Wednesday and Friday the betrayal and Passion of Christ. Although this simple primitive conception gave place in time, as feasts were introduced and multiplied, to an annual calendar, the week always retained its importance; this is particularly seen in the Divine Office in the hebdomadal division of the Psalter for recitation. Amalarius preserves for us the particulars of the arrangement accepted in the chapel royal at Aachen in 802 by which the whole Psalter was recited in the course of each week. In its broader features the division was identical with that theoretically imposed by the Roman Breviary until the recent publication of the Apostolic Constitution "Divine afflatu" on 1 Nov., 1911. Moreover, it appears from Amalarius that the Carlovingian arrangement was in substance the same as that already accepted by the Roman Church. Already in the sixth century, St. Benedict had clearly laid down the principle that the entire Psalter was to be recited at least once in the week; indeed a similar arrangement was attributed to Pope St. Damasus. The consecration of particular days of the week to particular subjects of devotion is also officially recognized by the special Office of the Blessed Virgin on the Saturday, by the Friday Masses of the Passion during Lent and by the arrangement of Votive Offices for special week days approved by Pope Leo XIII. For a long time in the early Middle Ages Thursday in the West was regarded as a sort of lesser feast or Sunday, probably because it was the day of the week on which the Ascension fell (cf. Bede, "Hist. Eccl.", IV, 25). Again the Breviary approved after the Council of Trent left certain devotion accretions to the Office, e.g. the Office for the Dead, Gradual Psalms, etc, to be said once a week, particularly on the Mondays of Advent and Lent.