What's the time of Mass?

The preconciliar Missal lays down that Mass may be said between Dawn and Midday. History isn't, of course, as simple as that . At an earlier period in Western Liturgy, Mass on fasting days was to be said after None ... at a time when None was in the afternoon. This is why the Oratio super populum in Lent is appointed to be also the Collect at Vespers. Celebrant and communicants would be fasting, and no doubt one reason why the times of services otched gradually earlier is the reponse of human frailty to this regimen. I hope to share some thoughts on another occasion about the Eucharistic Fast. For the moment, suffice it to say that Mass in the morning was the general rule until Pius XII permitted evening masses, thereby undermining one of the most insistent campaigns which Catholic Anglicans had been waging since the start of the Catholic Revival.
Of course one accepts that this flexibility has been one of God's new gifts to his Church in the last couple of generations. I do not know if there is any significant body of Western Christian that condemns it; the SSPX certainly countenances evening Masses. But I wonder if we ought to regard it as the norm, so that when arranging the times of Mass in Retreats or pilgrimages we just fix them for any old time. I suggest that, if the Hermeneutic of Continuity means anything to us, we ought to start off with a prejudice in favour of beginning the day with Mass. This doesn't mean getting up at the crack of dawn; on a retreat I can see no reason why Mass should not be at 8.30 and be followed by a comfortable breakfast. We shouldn't let what the catering staff have grown accustomed to providing become a barrier to facing the Lord who comes to us with the rising of the sun so that the Mass is what our entire day springs out of. And on our Lourdes pilgrimage, it was entirely natural for us to meet for Mass in the evening of the Monday of our arrival. But I wonder whether it was necessary to delay the Tuesday's Mass until the evening.
Nor am I suggesting that later masses which suit workers, or those who do not live near the church which they attend, are anything but a Good Thing which should continue. I'm not suggesting anything which would be awkward or uncomfortable or make Mass less easy to attend. I'm simply asking whether some of us could benefit in our own personal discipline from what nearly 2,000 years of Christianity did find to be a manageable norm.