With the other books of the we first read the book to determine the date, so determining the date first to understand Revelation is kind of like putting the cart before the horse.
A few of date indicators within Revelation include John being requested to "measure" the temple and those that worship in it (11:1), indicating that the temple was not yet destroyed at the time of the vision, ie before 70AD.
The 2 witnesses in that chapter also prophesy in Jerusalem "a thousand two hundred and threescore days".
Jerusalem is identified in v.8, and in the passage appears to be populated and not yet destroyed.
Having identified the "great city" of 11:8 as Jerusalem, we already have the identity of the harlot in chapter 17.
We are told a great deal about this harlot, and it would be difficult to miss her identity.
The harlot seems alive and well as she sits on the beast (17:3), and the relationship between the woman and the beast has not yet become openly hostile.
This beast is identified as Rome in 17:9 by the seven mountains, but John seems to hope that mainly Christians will understand this identification, ie "the mind which hath wisdom".
In 17:16 John also predicts the Roman destruction of Jerusalem as future.
I have only covered these two chapters, because they are fresh in my mind from a recent conversation with @OMC, but the whole book is full if similar date indicators.
We could of course consider the possibility that Revelation was written after these events, explaining the past rather than predicting the future.
If we were discussing Moses writing Genesis that would be the case, but with Revelation I doubt it.
We are told that the book is about things that must shortly come to pass, not events of the past.
For people interested in exploring this view of Revelation I will also post a sermon by Chuck Baldwin.
At this point in time I find no reason not to endorse the things said in this sermon:
When reading Revelation 11, pay attention to the "woes".
Revelation 11:14 - The second woe is past; and, behold, the third woe cometh quickly.
What happens after each woe in the book of Revelation?
Here's the A.I. quick summary description:
The three woes in the Book of Revelation are severe judgments pronounced by an angel flying overhead (Revelation 8:13) that correspond to the fifth, sixth, and seventh trumpet blasts. These events represent escalating divine wrath intended to punish evil and spur repentance among the inhabitants of the earth before the final establishment of God’s kingdom.
The First Woe (Fifth Trumpet): This woe involves the release of demonic locusts from the Abyss (Revelation 9:1-11). These creatures, described with human and scorpion-like features, are permitted to torment non-believers for five months but are forbidden to kill them. This judgment highlights God's sovereignty by limiting the duration and scope of the suffering.
The Second Woe (Sixth Trumpet): This woe is triggered by the release of four angels bound at the Euphrates River (Revelation 9:13-21). These angels lead a cavalry of 200 million troops that kill one-third of humanity through fire, smoke, and sulfur. Despite this massive loss of life, the survivors refuse to repent of their idolatry and murders.
The Third Woe (Seventh Trumpet): This final woe marks the consummation of God’s plan and the end of judgment (Revelation 11:15-19). It signals the transition to Christ’s eternal reign, the defeat of evil, and the establishment of God’s kingdom on earth. This woe also encompasses the pouring out of the seven bowls of wrath (Revelation 16), representing the final and complete judgment on sin.