[166.] Likewise, especially if Holy Communion is distributed during such celebrations, the diocesan Bishop, to whose exclusive competence this matter pertains, must not easily grant permission for such celebrations to be held on weekdays, especially in places where it was possible or would be possible to have the celebration of Mass on the preceding or the following Sunday. Priests are therefore earnestly requested to celebrate Mass daily for the people in one of the churches entrusted to their care.While the responsibility does fall on the local bishop to regulate such celebrations, RS does specifically state that permission for such "must not easily" be granted. Now, one could very well use the "pastoral reasons" clause to justify these services. One can certainly understand taking into consideration the faithful who regularly assist at daily Mass and are daily communicants. But, daily Mass assistance, while laudable and strongly encouraged, is not obligatory (unless, of course, a Holy Day of Obligation falls during the week).
However, there is another liturgy that many parishes tend to overlook, tend to forget: the Liturgy of the Hours. The Liturgy of the Hours is not just reserved to clergy and religious. The faithful can certainly make use of this particular liturgy, especially when daily Mass is not available. It involves the singing of hymns, the chanting/recitation of psalms, the proclamation of a scriptural reading and various other prayers. Most parishes schedule their weekday Masses either in the morning, at noon or in the evening. The Liturgy of the Hours is normally prayed in the morning, at noon or in the evening. Pope Benedict XVI frequently presides over the Liturgy of the Hours, specifically Vespers, doing so on the Vigil of the Solemnity of Sts. Peter and Paul, the Vigil of the First Sunday of Advent and the Vigil of the Solemnity of Mary the Mother of God, just to name a few occasions.
Parishes could prepare little booklets ahead of time to help the faithful pray the Liturgy of the Hours when they know that their pastors will be out of town or unavailable for Mass. In fact, those parishes that have a tradition of having a Holy Hour could very well use this time to introduce the faithful to this prayer of the Church.