I got a question via e-mail:
What exactly is required for the fulfillment of a Holy Day? I ask this because those who attend both the Ordinary and Extraordinary forms of Mass can get into ackward situations with the celebration of the Ascension on two different days in certain dioceses. Are those who are not able to make it to the Ascension Thursday Mass in the EF obliged to attend the Ordinary Form the following Sunday?
Also, can a cleric pray the Liturgy of Hours, with its calander, and attend the Extraordinary Form of Mass on these same days (Ascension Thursday and Ascension Sunday), or coversely pray the Roman Breviary and attend the Ordinary form on these days?
First, the local guidelines for your diocese should be observed for Holy Days. However, if there is a Holy Day of Obligation, you should strive to fulfil it regardless of which Rite of Holy Mass you must attend. Just because a fellow might prefer the TLM, that does not dispense him from his obligation if there is no TLM available (unless there are other serious circumstances… which in 99% of the times are aren’t).
Second, a cleric can do anything he wants in regard to the office now.