The most probable construction seems to be that the unknown author meant that the Pastor of Hermas was composed within his own memory.

Volkmar is doubtless right in saying [Endnote 265:1] that he meant to distinguish the work in question from the writings of the Prophets and Apostles, but still the double use of the words 'nuperrime' and 'temporibus nostris' plainly indicate something more definite than merely 'our post-apostolic time.' If this had been the sense we should have had some such word as 'recentius' instead of 'nuperrime.' The argument of 'Supernatural Religion' [Endnote 265:2], that 'in supposing that the writer may have appropriately used the phrase thirty or forty years after the time of Pius so much licence is taken that there is absolutely no reason why a still greater interval may not be allowed,' is clearly playing fast and loose with language, and doing so for no good reason; for the only ground for assigning a later date is that the earlier one is inconvenient for the critic's theory.

The other indications tally quite sufficiently with the date 170-190 A.D.Basilides, Valentinus, Marcion, the Marcionites, we know were active long before this period.

The Montanists (who appear under the name by which they were generally known in the earlier writings, 'Cataphryges') were beginning to be notorious, and are mentioned in the letter of the Churches of Vienne and Lyons.
Miltiades was a contemporary of Claudius Apollinaris who wrote against him [Endnote 266:1].

All the circumstances point to such a date as that of Irenaeus, and the conception of the Canon is very similar to that which we should gather from the great work 'Against Heresies.' If this does not agree with preconceived opinions as to what the state of the Canon ought to have been, it is the opinion that ought to be rectified accordingly, and not plain words explained away.
I can see no sound objection to the date 170-180 A.D., but by adding ten years to this we shall reach the extreme limit admissible.
I do not know whether it is necessary to refer to the objection from the absence of any mention of the first two Synoptic Gospels, through the mutilated state of the document.