Note 18 — Chapter XXXVII

Dias que no son dobles: in church terminology, feast days whereof the canonical offices are observed according to double rite—or duplex feasts, as sometimes styled in English liturgical works. In church calendars, the rite to be followed every day of the year is determined (according to fixed rules) with a view to its greater or less solemnity. The various designations thus employed are: simple, or simplex; semi-double, or semi-duplex; double, or duplex, and these may be minor or major; major double of the second class; and major double of the first class. Of this last sort are the most solemn feasts, as Christmas, Easter, Pentecost; while a feast day of simple rite is of the lowest class.—Rev. T. C. Middleton, O.S.A.

Cf. Addis and Arnold’s Catholic Dictionary, art. “Feasts” and “Feria,” where full details, and the origin and application of the terms, are given.