Now the Latin Mass Society has obtained a formal response from the Pontifical Commission Ecclesia Dei. The New Liturgical Movement has posted the full text of the reply and the LMS press release. The PCED points out that the matter is still under study and that the present response should be taken without prejudice to further clarification to be issued by the Commission.
The key points of the response are:
1. The legitimate use of the liturgical books in use in 1962 includes the right to the use of the calendar intrinsic to those liturgical books.This is a welcome clarification which will set some people's minds at rest. It is perfectly all right to celebrate the Epiphany and Ascension, for example, according to the usus antiquior on the traditional days, as many parishes have chosen to do. This is in fact a good introduction for many people to the Traditional Latin Mass.
2. While in accordance with Canon 1246 §2 of the Code of Canon Law the Episcopal Conference can legitimately transfer Holydays of obligation with the approbation of the Holy See, it is also legitimate to celebrate the Mass and Office of those feasts on the days prescribed in the calendar of the liturgical books in use in 1962 with the clear understanding that, in accordance with the legitimate decision of the Episcopal Conference, there is no obligation to attend Mass on those days.
3. Thus, in accordance with nn. 356-361 of the Rubricae Generales Missalis Romani of 1962, it is appropriate to celebrate the external solemnity of Holy Days on the Sunday to which they have been transferred by the Episcopal Conference, as has been customary in many other countries hitherto.
It should be noted that the celebration of the feast again on the Sunday as an external solemnity is "appropriate" and therefore not obligatory.