The divergence between the Ordinary and Extraordinary Form calendars, combined with the widespread practice of transferring feasts and holyday obligations to the nearest Sunday, raises questions about how to apply Canons 1246 and 1247 in the context of the Extraordinary Form. Can the Mass of the day in the Extraordinary Form Calendar be said when the feast has otherwise been transferred? Can it be said on the Sunday to which the feast was transferred? When need one attend Mass?
The Latin Mass Society of England and Wales raised just those questions with the Pontifical Commission Ecclesia Dei soon after the promulgation of Summorum Pontificum. They received a response to the effect that (1) One may always say the E.F. Mass for a particular on the day indicated by the E.F. calendar; (2) one may also say the E.F. Mass on the day to which the feast has been transferred; and (3) the obligation under Canon 1247 to hear Mass applies only on the day to which the obligation is, as a general matter, assigned by the episcopal conference and the local ordinary.
Thus, one can say the E.F. Mass of the Ascension on Ascension Thursday; you can say the same Mass again on “Ascension Thursday Sunday”; but unless you live in a diocese where Ascension Thursday is itself a day of obligation, you are only obliged to attend Mass on the Sunday. The E.F. Mass said on the original feast day is celebrated as an “external solemnity
Here are the texts of the LMS’s and the PCED’s letters:
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HE Darío Cardinal Castrillón Hoyos,
President, Pontifical Commission Ecclesia Dei,
Palazzo del Sant’ Uffizio 11,
00120 Vatican City State.
3 July 2008
The recent announcement by the Bishops of England and Wales that your dicastery has clarified to them “that in the Roman Rite, whichever Form of the liturgy is being celebrated, the Holydays of Obligation are held in common” has given rise to a good deal of confusion and some disquiet amongst our membership.
Whilst we most certainly wish to maintain and to manifest hierarchical communion with our bishops and through them our unity of faith with our brothers and sisters in the faith, there are a number of pastoral reasons – not the least the hope of reconciliation with those not in a regular relationship with the Church – that suggest that this question not be interpreted with a rigour that confuses or scandalises our weaker brethren.
It also seems that the statement of the Bishops of England and Wales does not sufficiently take into account the liturgical laws intrinsic to the liturgical books in use in 1962. Therefore, for the good of souls and the preservation of charity, on behalf of the Latin Mass Society of England and Wales, I request your authoritative clarification on the following points:
I. That the legitimate use of the liturgical books in use in 1962 decreed by the Sovereign Pontiff in Summorum Pontificum includes the right to the use of the calendar intrinsic to those liturgical books.
II. That, whilst in accordance with Canon 1246 the Episcopal Conference with the approbation of the Holy See legitimately transfers Holydays of Obligation or suppresses the obligation of Holydays, it is 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.
III. That, 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.
As the task of compiling the Ordo for 2009 is upon us, I would be most grateful for Your Eminence’s clarification of these questions as soon as is possible.
Your servant in Christ,
Latin Mass Society
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PONTIFICIA COMMISSIO « ECCLESIA DEI »
Rome, 20 October 2008
Dear Mr. Chadwick,
I wish to acknowledge receipt of your letter of 3 July 2008 in which you raise certain questions pertaining to Holydays of obligation.
In the first instance I wish to point out that the question of the liturgical calendar to be followed for the use of the liturgical books of the extraordinary form of the Roman Rite is one that will continue to be studied by this Pontifical Commission. Hence present responses should be understood without prejudice to any subsequent clarifications which may be eventually made by this Pontifical Commission.
With regard to your queries we may state that:
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.
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.
With prayerful best wishes I remain,
Sincerely yours in Christ,
Rev. Msgr Camille Perl
In a few contexts it may be obligatory to say the feast on the following Sunday.
 Latin Mass Society of England and Wales, Transferred Holydays of Obligation: Texts of the LMS’s Dubium and the Vatican’s Official Response, http://www.lms.org.uk/resources/articles-on-the-mass/transferred-holydays-of-obligation-correspondence.
 See Rev. John Zuhlsdorf, External (TLM) Observance of Corpus Christi on Sunday… yes? no?, Fr. Z’s Blog, June 2, 2013, http://wdtprs.com/blog/2013/06/external-tlm-observance-of-corpus-christi-on-sunday-yes-no.