Considering the truth that the Book of Revelation was revealed by God and that the prophet John correctly wrote down the truths he was shown, we can see that the time related information in the book (internal to the book) is the most important criteria for dating the writing of the book.
Such information gained from the contents of the book is often called "internal evidence", and such internal evidence has a higher priority and carry more weight than the so called "external evidence", that is, information about the matter in other sources and other works.
Obviously this date would completely prevent anyone from accepting the Preterist theory that the events described in Revelation took place some 25 years earlier in 70 AD. From Irenaeus' work, Against Heresies, Book 5, Chp. For it has in itself the predicted number, and is composed of six letters, each syllable containing three letters; and [the word itself] is ancient, and removed from ordinary use; And besides this, it is an ancient name, one worthy of credit, of royal dignity, and still further, a name belonging to a tyrant.
A hard look at Joshua Harris's crusade against Christians dating. We argue against eliminating it for mate selection and marriage preparation Revelation 4 New International Version (NIV) The Throne in Heaven.
4 After this I looked, and there before me was a door standing open in heaven.
When after the death of the tyrant (previously identified as Nero) he removed from the island of Patmos to Ephesus, he used to journey by request to the neighboring districts of the Gentiles, in some places to appoint bishops, in others to regulate whole churches, in others to set among the clergy some one man, it may be, of those indicated by the Spirit.
The debate took place on December 10, 2007 at the annual Pre-Trib Study Group meeting in Dallas, TX. Hitchcock's PHD dissertation on the date of the book of revelation.