Frequently asked questions no 4: Why aren’t the hours set out in the order in which they are said in the Monastic Diurnal and breviary? Whis Sunday Prime separated from the other days of the week?

One of the oddities of most monastic Office books is the ordering of the hours, as rather than starting with Sunday Matins (which St Benedict specified in his Rule as the starting hour of the week), they start with Monday Prime.  Newcomers to the Office also often struggle to find Sunday Prime, since it is placed after Saturday Lauds, rather than with the other days of Prime. 

The reason for this arrangement has to do with the history of the breviary, where the psalter was originally literally the book of psalms with a few insertions for the various hours, together with the influence of the Roman Office, which originally largely followed the Bible order of the psalms. 

The section of the Office book containing the opening and other standard components of each hour is known as the psalter section, and it is broadly organised around the numerical order of the psalms as they appear in the Bible.  It starts with Monday Prime because that hour starts with Psalms 1 and 2.  

The problem with this arrangement though, is that the Benedictine Office does not really go in strict numerical sequence, so some compromises have to be made.  

The system is useful if you are looking for a particular psalm, and since traditionally Benedictines were expected to know the entire psalter (and Office) by heart, the organisation of the book probably wasn't seen as that important.

For the modern layperson though, the net result is confusing at first, as the order of the hours in Benedictine books such as the breviary and Diurnal, the order of the psalter section by hour typically goes like this: 

Monday to Saturday Prime (Psalms 1-2, 6-19)

Sunday to Saturday Matins (not included in the Diurnal) and Lauds (Psalms 3, 5, 20-89, 91-108, 142, 148-150)

Sunday Prime to None (Psalm 118)

Monday Terce to None (Psalm 118 continued)

Tuesday to Saturday Terce to None (Psalms 119-127)

Sunday to Saturday Vespers (Psalms 108-147 minus those used at other hours)

Compline (Psalms 4, 90, 133).

By contrast, the order in which the hours are actually said is Matins, Lauds, Prime, Terce, Sext, None, Vespers and Compline.