Institutiones

Guides to the liturgical calendar

What the colours, ranks and cycles on every page of the calendar mean, in both the Ordinary Form and the 1962 Missal.

• De coloribus liturgicisThe liturgical colours and when each is wornWhite, red, green, violet, rose and black: what each liturgical colour means, when the Church uses it, and how the 1962 Missal differs.
• De gradibus celebrationumSolemnity, feast, memorial: the ranks of the liturgical dayHow the Ordinary Form ranks its celebrations, from solemnities to optional memorials, and what decides which one a day keeps when two fall together.
• De cyclis lectionumSunday cycles A, B and C, and weekday years I and IIWhy the Sunday readings follow a three-year cycle and the weekday readings a two-year one, how to tell which year it is, and when each begins.
• De tempore per annumOrdinary Time: why it has two parts and thirty-three or thirty-four weeksWhat Ordinary Time is, why it is split around Lent and Easter, and how its weeks are counted so that the last always ends with Christ the King.
• De SeptuagesimaSeptuagesima: the pre-Lent season of the 1962 MissalSeptuagesima, Sexagesima and Quinquagesima: the three Sundays before Lent in the 1962 Missal, what changes in the Mass, and when they fall.
• De classibus dierum liturgicorumThe classes of feast in the 1962 MissalFirst, second, third and fourth class days in the 1962 Missal, commemorations, and how they compare with the ranks of the Ordinary Form.
• De duobus calendariisThe Ordinary Form and 1962 calendars comparedWhy the same saint can fall on different days in the two Missals, which seasons and feasts each keeps, and how to read both on one page.