Occurrence, Concurrence

Occurrence is had when on the same day two Offices occur; and then from title IV of the Rubrics to be observed, and from the table of occurrence which was drawn up by the Sacred Congregation of Rites, Decree of January 23, 1912, it is to be determined concerning which Office is to be made, and whether nothing is to be had concerning the other, or whether only a commemoration is to be made of it, or whether it is to be placed on another free day.

Occurrence of feasts can be had in two ways: by their accidental translation, or by their perpetual replacement. Rubrics to be observed, titles III-IV.

"The concurrence of an Office is always to be attended to in second Vespers, how the Office is to be ordered with the following day. Therefore, when some Office is said to concur with another, it is understood of the preceding in second Vespers with the following in first." General Rubrics of the Breviary, title XI, n. 1.

The aforesaid ordering of Offices is to be determined according to the table of concurrence drawn up by the Sacred Congregation of Rites in the cited Decree.