As everyone said, it’s all a matter of conjecture.
The common idea throughout most of Church history is that Revelation might have been written during or after the reign of Domitian (AD 81-96). St. Irenaeus (who heard St. Polycarp, who in turn was supposedly a disciple of John the apostle) is our earliest source to claim this: “For that was seen no very long time since, but almost in our day, towards the end of Domitian’s reign.” (
Against Heresies 30) This is one of those places where most modern scholars actually accept - or see no reason to dispute - early Church tradition.
That being said, some scholars nowadays do try to pin an earlier date for the work, usually somewhere around the reign of Nero of Vespasian (AD 60s-70s). They argue that the book fits in with the last days of Nero and the impression Nero made on his contemporaries (I mean, the Beast of Revelation 13 is commonly identified with him). (But then again, Nero’s shadow looming over Revelation is not necessarily an indicator of an AD 60s-70s date: I mean, Nero was such a famous emperor - the aristocrats and the Christians didn’t like him, but the commoners did - that people believed or feared that he would return eventually: the belief in
Nero redivivus.) Those who push for the earlier date would answer St. Irenaeus’ claim by saying that maybe he was mistaken; maybe he was just guessing like we do now, maybe the memories were muddled by the time Irenaeus wrote. Plus, his dating of Revelation is tied in with his idea that the author was John the apostle. In other words, if John son of Zebedee was not the author of Revelation but a different John, then that may potentially put his claim into question.
Given how the work allows for both intepretations, a further minority segment of scholars would say, what if Revelation actually came in two editions? They would say that the work would have been originally written during the 60s-70s, but was revised later during the time of Domitian.
This is my personal opinion.
Personally, I side with the majority on this one. There’s after all the testimony of Irenaeus. (There are later traditions - from the 4th and the 11th centuries - that claim that John’s exile actually took place in Nero’s reign or even during the reign of Claudius (AD 41-54), but the fact that they’re much later than Irenaeus makes me consider them less seriously.) Plus, just as I mentioned while the shadow of Nero looms over the work, that doesn’t necessarily preclude the work being written after his time - since Nero was still in the minds of most people during the decades following (again, the
Nero redivivus idea). In addition, a late 1st century date would allow enough time for the development (or rather, decline) of the seven churches mentioned in the work rather than a mid-1st century date.