Today, in the Roman Rite, is traditionally the Vigil of the Solemnity of SS Peter and Paul.
Before the changes initiated under Pius XII began, S Irenaeus had been put onto this day. So, in the admirable ORDO published by the Saint Lawrence Press (giving the Roman Rite as it was circa 1939), Mass today is of that Saint, with commemorations of two octaves and of the Vigil. Or ad libitum, it is of the Vigil, with commemorations of the Saint and of the octaves.
In 1962, S Irenaeus was moved to July 3 so as to unclutter the observance of the Vigil (octaves had by now been abolished).
Less than a decade after this, the Novus Ordo Calendar put S Irenaeus back onto today.
Summary: (1) Today is the real festival of S Irenaeus (as well as the Vigil of the Apostles). He spent less than a decade (1962-1970) in exile on July 3. As it happens, the Novus Calendar agrees with the pre-Pius XII Calendar. What the 1962 calendar provides is both 'untraditional' AND out of sync with what the Novus part of the Roman Rite does. This is a matter of everybody in the regiment except my 1962 Johnny being out of step.
(2) Would it really be an act of base treachery to Tradition to correct the 1962 Calendar, at least in those places where the pre1962 Calendar and the Novus Calendar are in agreement with each other against 1962?
(3) The Roman Rite, like the Byzantine Rite, should be more welcoming to the custom of observing two commemorations on the same day. As it was before the 1960s.
(4) As happened before Pius XII and Bugnini, there should be more ad libitum in the 1962 missal.
(5) Would it be the ultimate crime to allow the use of Last Gospels of commemorated Sundays and Vigils, as used to happen before Pius XII let Mgr Bugnini loose on the Roman Rite?
But there is yet another Saint with a claim upon today!! We will consider him tomorrow, in connexion with the Apotles SS Peter and Paul.