The new Scottish Proprium sanctioned for the Roman Catholic province of St Andrews in 1903 contains many of the old Aberdeen collects and antiphons.
The Breviary itself is divided into four seasonal parts - winter, spring, summer, autumn - and comprises under each part (1) the Psalter; (2) Proprium de Tempore (the special office of the season); (3) Proprium Sanctorum (special offices of saints); (4) Commune Sanctorum (general offices for saints); (5) Extra Services.
The Proprium de Tempore contains the office of the seasons of the Christian year (Advent to Trinity), a conception that only gradually grew up. There is here given the whole service for every Sunday and week-day, the proper antiphons, responsories, hymns, and especially the course of daily Scripture-reading, averaging about twenty verses a day, and (roughly) arranged thus: for Advent, Isaiah; Epiphany to Septuagesima, Pauline Epistles; Lent, patristic homilies (Genesis on Sundays); Passion-tide, Jeremiah; Easter to Whitsun, Acts, Catholic epistles and Apocalypse; Whitsun to August, Samuel and Kings; August to Advent, Wisdom books, Maccabees, Prophets.
The Proprium Sanctorum contains the lessons, psalms and liturgical formularies for saints' festivals, and depends on the days of the secular month.
As something like 90% 'of the days in the year have, during the course of centuries, been allotted to some saint or other, it is easy to see how this section of the Breviary has encroached upon the Proprium de Tempore, and this is the chief problem that confronts any who are concerned for a revision of the Breviary.
The psalms have already been dealt with, but it may be noted again how the multiplication of saints' festivals, with practically the same special psalms, tends in practice to constant repetition of about one-third of the Psalter, and correspondingly rare recital of the remaining two-thirds, whereas the Proprium de Tempore, could it be adhered to, would provide equal opportunities for every psalm.
The difficulty of harmonizing the Proprium de Tempore and the Proprium Sanctorum, to which reference has been made, is only partly met in the thirty-seven chapters of general rubrics.