Do clerics commit a sin if they do not recite the liturgy of the hours?

According to the [Code of Canon Law 1174](http://www.intratext.com/IXT/ENG0017/_P47.HTM) , priests and deacons are obliged to recite the liturgy of the hours (divine office). If they do not do so, do they commit a sin (moral law)? Or is it only a "legal transgression" (Church law)? The text of the Canon Law does not seems to specify the consequence. > Can. 1174 §1 Clerics are obliged to recite the liturgy of the hours, in accordance with Can. 276, §2, n. 3; members of institutes of consecrated life and of societies of apostolic life are obliged in accordance with their constitutions.