The obligation of certain individuals within the Church to celebrate the Liturgy of the Hours is deeply rooted in ecclesiastical tradition. Although various aspects have been emphasized to different degrees over time, the fundamental idea has persisted. The Second Vatican Council rediscovered many facets that had fallen out of focus. In the present, important legal aspects have been added. Among other things, the study provides a compilation of the liturgical books that contain the local celebrations applicable in the dioceses of the German-speaking region. Furthermore, it presents and analyzes the complementary norms of the bishops' conferences worldwide that define the extent of the obligation of permanent deacons to the Liturgy of the Hours.