Now I'm not sure. Una Voce has the twelfth Sunday (above) up for this week, but the Fr. at our Chapel was following what must have been the feast you mention. I had meditated on what's posted here before going so I'm a bit clueless.
If anyone could straighten me out I'd appreciate it.
My calendar, for the day of August 22, 2004, states:
Twelfth Sunday
after Pentecost-G (II)
The Immaculate
Heart of Mary-W (I)
Sts. Timothy, Hippolytus
& Symphorianus
Marytrs-R (Comm.)
Una Voce has the twelfth Sunday (above) up for this week, but the Fr. at our Chapel was following what must have been the feast you mention.
First, I'm no expert on which propers to use at Mass. That said, I believe that what Grey Ghost II posted about the precedence (feasts of Our Lord take precedence over feasts of Our Lady) is correct.
Feasts in the
1962 calendar can be of the first class, second class, third class, or commemoration. (Some calendar reform was done in the 1950s.) When feasts of the same class fall on the same day, as happened yesterday, when the 12th Sunday after Pentecost and the Immaculate Heart of Mary both fell on August 22, then a feast of Our Lord takes precedence over a feast of Our Lady.
That rule of precedence being stated, I believe that if the Mass of the feast taking precedence has already been said, the priest may (I'm not sure about this) say the Mass of the feast with lesser precedence. Thus, if the Mass for the 12th Sunday after Pentecost has already been said, then the priest may say the Mass for the Immaculate Heart of Mary.
I've used the
Catholic Time site, the
Globusz.com pages explaining the Breviary, the
Breviary entry in the Catholic Encyclopaedia, and the
Reform of the Breviary entry in the Catholic Encyclopaedia in composing this post.
If anyone has more accurate information about this, I welcome corrections