Here's the quote from Adversus Haereses by Irenaeus regarding the date of the book of Revelation in the context of the Apostle John's life:
"We will not, however, incur the risk of pronouncing positively as to the name of Antichrist; for if it were necessary that his name should be distinctly revealed in this present time, it would have been announced by him who beheld the apocalyptic vision.I went and checked the Greek text preserved by Eusebius and it's ambiguous. The part about "being seen" could be translated in three ways:
For [it or he] was seen not very long time since, but almost in our day, towards the end of Domitian's reign."
- Saint Irenaeus, Adversus haereses 5, 30, 3
For it, that is the vision, was seen not very long ago, but almost in our day, towards the end of Domitian's reign.
For it, that is the written book, was seen not very long ago, but almost in our day, towards the end of Domitian's reign.
For he, that is the Apostle John, was seen no very long ago, but almost in our day, towards the end of Domitian's reign.
So which is it? I have no idea. I just think that it's interesting that the classic Patristic text for proof that John wrote the Apocalypse around A.D. 95 is ambiguous.
The interpretive tradition has favored Option #1 (because that is the spin that Eusebius gave it).
Robert Gundry has done a lot of great work on demonstrating that Eusebius has manipulated many texts in order to discount the book of Revelation. Gundry goes at great lengths to show that Eusebius created the dichotymy between "John the Apostle" and "John the Elder" in order to discount the book of Revelation because of its supposed millenialism.
I recommend the article to you because I find it quite compelling:
Gundry, R.H. "The apostolically Johannine pre-Papian tradition concerning the Gospels of Mark and Matthew," in Gundry R.H., The old is better: New Testament essays in support of traditional interpretations. Tübingen: Mohr Siebeck, 2005, pp. 49-73.I think that Saint Irenaeus does not necessarily close the case on this question since we don't know what he meant.