IV class
White
Mass of the I Sunday after Epiphany; Gloria; no Credo; preface of the Epiphany
The principal parts of the office during these seasonal ferias (until January 12) are from January 6, but are all listed together for convenience in the Ordinarium, under Time of Epiphany
Matins: Invitatorium and Hymn from the Time of Epiphany; psalms and antiphons of the feria; scripture lessons of the calendar day; Te Deum
Lauds: Psalms and antiphons of the feria; capitulum and following from Time of Epiphany; Benedictus antiphon proper
Prime: Psalms and antiphons of the feria; verse Qui apparuisti
Hours: Psalms and antiphons of the feria; capitulum and following from Time of Epiphany
Vespers: Psalms and antiphons of the feria; capitulum and following from Time of Epiphany; Magnificat antiphon proper
Compline: Of the feria
IV class Votive Masses are permitted, but IV class Requiem Masses are not (until January 13 inclusive)