If this be the correct interpretation, there is no uncertainty about the date and authorship of the book.
The preface or title closes with the words, "Blessed is he that readeth, and they that hear, the words of this prophecy, and keep those things which are written therein; for _the time is at hand_." And then the book opens with an apostolic salutation to the Churches, and a fervent ascription of praise to Jehovah, and to the risen and exalted Messiah and Redeemer.
"John to the seven Churches which are in Asia (Churches planted by Paul years before): Grace unto you, and peace, from him which is, and which was, and which is to come; and from Jesus Christ, the faithful witness, the first begotten from the dead, and the prince of the kings of the earth. Unto him who loved us, and washed us from our sins in his own blood, and hath made us kings and priests unto God and his Father; to him be glory and dominion for ever and ever."
"I John, who also am your brother, and companion in tribulation, and in the kingdom and patience of Jesus Christ, was in the isle that is called Patmos, for the word of God, and for the testimony of Jesus Christ." "I was in the spirit on the Lord's day." (To be "in the spirit on the Lord's day" is in harmony with evangelical Christianity, and quite meaningless apart from it. The first day of the week is, undoubtedly, called the Lord's day, because on that day He rose from the dead; and bread has been broken and wine drunk on that day, in obedience to His commands, and in remembrance of His death, ever since the day of Pentecost.)
"I am he that liveth, and was dead; and, behold, I am alive for evermore, and have the keys of hades and of death."
"The Lion of the tribe of Juda, the Root of David, hath prevailed to open the book, and to loose the seals thereof."
"And I beheld, and, lo, in the midst of the throne ... a Lamb as it had been slain; and they sung a new song, saying, Thou art worthy to take the book, and open the seals thereof: for thou wast slain, and hast redeemed us to God by thy blood out of every kindred, and tongue, and people, and nation."
"Worthy is the Lamb that was slain to receive power, and riches," &c.
"Blessing, and honour, and glory, and power, be unto him that sitteth upon the throne, and unto the Lamb, for ever and ever."