Basically a calendar needed for the daily celebration of the proper Mass and Office in use throughout the Roman rite. In a ready, abbreviated format, it not only regulates the annual interplay of the temporal and sanctoral cycles, the fixed and moveable feasts, but it also notes any peculiar rubrics and gives seasonal pastoral reminders as needed. Because of special liturgical offices, local churches and monastic groups may vary from the Roman Ordo. The modern Ordo is but the development of local calendars and priests' rubrical and pastoral directories; it became a necessity after Trent decreed a uniform liturgy.
[r. t. callahan/eds.]