The institute was called Mercedarians and was solemnly approved by Gregory IX, in 1230. Its members were bound by a special vow to employ all their substance for the redemption of captive Christians, and if necessary, to remain in captivity in their stead.
But wait, you say, today is the Feast of the Angelic Doctor, St. Thomas Aquinas. Right? Well, yes, it is in the revised calendar published in 1969. His traditional feast day is March 7.
Any day is a good day to honor one of Christ's saints, so one can legitimately ask why it matters. But why was the calendar reordered as it was? Before his election to the Papacy, Joseph Cardinal Ratzinger pointed to a process much like the process that produced the new missal:
Ratzinger cited the reform of the liturgical calendar as an example of "the armchair strategy of academics, drawing up things on paper which, in fact, would presuppose years of organic growth." This approach was "one of the weaknesses of the postconciliar liturgical reform." Those responsible, he said, simply "did not realize how much the various annual feasts had influenced Christian people's relation to time. In redistributing these established feasts throughout the year according to some historical arithmetic -- inconsistently applied at that -- they ignored a fundamental law of religious life."
Thomas E. Woods, Jr.-- Benedict's Revolution: The Return of the Old Latin Mass
And there's the rub. Centuries of tradition, and the organic development of liturgy, feasts, fasts, rhythms and seasons all dissected, reordered, sanitized as though all of it was completely arbitrary. The normal course of growth, and the expectations of the faithful, were completely unsettled. The result has not been positive, and was not compelled by the council nor even by the new missal itself.
Should modern saints be included in the traditional calendar? Of course. How? The way it was always done-- integrated by the Church into the calendar while consistent with the handed-down tradition.
For those who wish a reform of the reform with a chance to succeed, the first--and relatively easy-- step, is to jettison the revised calendar, use the traditional calendar of the West, and add those saints' days Rome wishes to incorporate in addition to those already established.
With respect, then the reforms contemplated by Sacrosanctum Concilium could be approached in an atmosphere of more confidence that they, too, would be faithful to what has been handed down.