The Decree of the Congregation of Rites promulgating the new General Roman Calendar establishes that proper calendars for offices and Masses are to be revised by "using as criteria the norms on the structure of the liturgical year." To facilitate and safeguard this work, the Congregation for Divine Worship intends to issue pertinent guidelines and norms.
Meanwhile for the year 1970 and until the editio typica of the individual liturgical books has been completed, the following are to be observed.
1 Celebrations that a particular calendar has in common with the General Calendar are to be carried out in the manner indicated in the General Calendar.
2 Proper celebrations presently listed in particular calendars are to be retained and the manner of observing them is to be the same as that of celebrations retained in the General Calendar, that is:
- Feasts of the first class retained in the new Table of Liturgical Days as solemnities are to become solemnities.
- Feasts of the second class retained in the new Table of Liturgical Days as feasts are to be celebrated as feasts.
- Feasts of the third class are to be regarded as obligatory memorials. For the year 1970, should one of these coincide with an obligatory memorial of the General Calendar, the celebrant has the option of choosing either one.
- Commemorations become optional memorials when they fall on a day allowing an optional memorial; otherwise (that is, when these commemorations fall on the date of a solemnity, feast, or obligatory memorial) they are to be omitted.
3 The norms just listed are to be applied also to any feasts of the blessed that
may belong to particular calendars.