I class
White
Holy Day of Obligation in the USA
The feast takes precedence over the Advent Sunday
Proper Mass; Gloria; Credo; commemoration of the Sunday; preface of the Blessed Virgin Mary Et te in Conceptione immaculata
Matins: Invitatorium Immaculatam Conceptionem; Hymn Praeclara custos; 3 Nocturns, all proper; Te Deum
Lauds: Sunday psalms of the 1st scheme with the proper antiphons of the Feast; Hymn O gloriosa virginum; commemoration of the Sunday
Prime: Ps 53 instead of Ps 117, verse Qui natus es, short lesson of Advent: Domine, miserere
Hours: Sunday psalms with antiphons from Lauds
II Vespers: Psalms from the Common with antiphons from Lauds; Hymn Ave, maris stella; commemoration of the Sunday
Compline: Of Sunday