Let’s wrap up the GILH’s approach to requirement:
30. It is most fitting that permanent deacons recite daily at least some part of the liturgy of the hours, to be determined by the conference of bishops. [See Paul VI, Motu Proprio Sacram Diaconatus Ordinem, 18 June 1967, no. 27.]
In the US, the USCCB determines what the deacons must pray.
31. a. Cathedral and collegiate chapters should celebrate in choir those parts of the liturgy of the hours that are prescribed for them by the general law or by particular law.
In private recitation individual members of these chapters should include those hours that are recited in their chapter, in addition to the hours prescribed for all sacred ministers. [See Inter Oecumenici 78b.]
Each religious order sets the tone for its own members:
b. Religious communities bound to the recitation of the liturgy of the hours and their individual members should celebrate the hours in keeping with their own particular law; but the prescription of no. 29 in regard to those in holy orders is to be respected.
Communities bound to choir should celebrate the whole sequence of the hours daily in choir; [See SC 95.] when absent from choir their members should recite the hours in keeping with their own particular law; but the prescriptions in no. 29 are always to be respected.
32. Other religious communities and their individual members are advised to celebrate some parts of the liturgy of the hours, in accordance with their own situation, for it is the prayer of the Church and makes the whole Church, scattered throughout the world, one in heart and mind. [See Acts 4:32.] This recommendation applies also to laypersons. [See SC 100.]