Seasons like Septuagesima I observe in the office but not at Mass. And I have to keep feasts like Corpus Christi and Ascension on their original day, or I would really be in trouble. Here and there one has to fudge: I really cannot work out what to do on the Second Sunday after Christmas, though the last Sunday of October can be patched back together again using older breviaries.
No doubt some of you would find my practice rather unconventional, but really it is not easy to harmonize one's liturgical life, and the blessings of using the more traditional breviary are considerable. Having been granted their use by Summorum Pontificum, I'm not really prepared to forgo them.