The book of Revelation is divided into parts, parallel accounts as it were. I am not the first to notice this. However, my analysis may vary from others in how I divide the book. For my purposes, not having a school of eschatology to defend, but just looking at the Bible for what it does say, I came realize a rule was in effect for differentiating parallel accounts: there has to be both a change of focus and a change of scene.
Because Revelation is written with overlapping parallel accounts, it cannot be read as a novel straight through. Doing that repeats several unique and specific events and confuses the sequence of any whole timeline approach. The manner of prophecy is like a limited view of each component in a complex movement. While it will be experienced in whole like listening to an orchestra: to foretell it is like to write a symphony section by section. Revelation is like reading the composition of a symphony by reading each written part -by part.
Discounting Johns narrative as a single account to order the events then sets each of the visions to be analyzed within their own context. Switching to the analogy of film, instead of looking at different major divisions as scene changes in a single movie; each parallel account -literally like another movie- films the future from a different vantage point in order to cover all the action occurring at different levels. Discerning the time each vision spans thus depends upon the evidence within each one. Historical time markers that are specific and unique, repeated specific and unique events and repeated time markers will allow for an assignment of time spans based on what the Bible has written.
The First parallel account has to do with the Churches. While each Church is physically present in the first century A.D., each Church's description includes a future promise in the Kingdom. Because of this aspect, chapers 2 and 3 can be viewed as being over 2000 years long and spanning the Church Age.
The Second parallel account is the Seal Chronology. While it starts with the description of the Heavenly Court, the focus changes as the Lamb opens the Seals (but not the scene). The first four Seals reveal the inception of the four horsemen and in Zechariah 6, you can see how these horsemen grow to be chariots of horses as they come out of Heaven and go forth to do their work in the world. This shows that the forces these horsemen represent grow over time. The Seal chronology starts in 4:1 and goes to the end of chapter 11. I maintain that the third woe is not expressed in this parallel account as John more than obeys the order to seal up what the seven thunders said and not write it down. I think the timeline for the Seals does not follow the seven years because of the pegging of the sixth Seal following the midweek point as per Jesus' Olivet Discourse in the Synoptic Gospel accounts. I allow that the Seal chronology make take a much longer time for it to be accomplished, and debating the nature of the first horseman, could have started as early as the nineteenth century with the industrial revolution.
The Third parallel account lies inserted in side the second almost as a sidebar issue. It goes from 11:1 to 11:13. Here the change of focus goes from the Seals to the Temple. There is also a change of scene to an earthly realm. John does not detail his measurements, but I would ask who is it that Ezekiel sees as the man in bronze who is measuring the Temple in Ezekiel 40:3 if not John. The Temple account is seven years long. The first half for the Gentiles, and the second for the two witnesses as God takes over. (We know the witnesses are in the second half, as they are killed by the beast of the Abyss loosed in the Fifth Seal.)
The Fourth parallel account focuses on Israel with a major scene change. It starts with the birth of our Savior and goes into the first half of the seventieth 'seven.' This encompasses verses 12:1-6 and takes about 2000 years.
The Fifth parallel account focuses on Satan with another scene change. Opening up Revelation 12:7 this event spans the next two verses; it describes a battle that allows us to give an approximate time to this event. Through the time of the flood, Satan was able to directly access God as told in Job. At Christs birth from the previous parallel account of the woman in Revelation 12:4, Satan is still in that heavenly realm. During Christs ministry Jesus describes a similar event to Revelation in Luke 10:18; both have Satan as the accuser displaced from access to Heaven. This happens sometime during Christs first advent when Jesus invades the domain of Satan, the strongman, and has power to bind him (and so cast out demons).
Coming to the close a similar event repeats and protection is afforded again for the woman for three and half years. This event chronicles protection for either half of the seventieth seven, or this is a repetition of a specific and unique event from the account of the woman: protection afforded Israel by God from Satan. Finally, there is the first definition problem, as this parallel account ties up with the offspring of Israel. This account of the dragon spans a period of time from Jesus ministry with his first advent to some time in the seventieth seven. This account ends with the opening of chapter 13:1 where the next character is introduced. The fifth parallel account lies directly over the fourth and likewise takes approximately 2000 years.
The Sixth parallel account from chapter 13 through chapter 16 focuses on the beasts emanating from the dragon. This parallel account spans the seven years of the seventieth 'seven.' This chronicles the offensive nature of the beasts and their destruction. This follows a major theme in the Bible, idolatrous worship as the most detestable practice and the consequence of Gods judgment for it. This account has a two-step fashion then, the first in chapter 13 covering the first half week enumerating the magnitude of the offence and a change of scene in chapter 14 which literally shows the consequences when God acts going to the end of 16 for the second half week. Within Gods active involvement on the earth, there is an elemental sequence. The scene change in chapter 14 shows Gods saving or harvesting of the earth. After that the scene changes to the pouring out of Gods wrath. This idea of saving and then destroying is the same as John the Baptist said of Christ gathering his wheat and burning the chaff. Jesus own parable of the weeds sown among the wheat follows the same course, the weeds are bundled, the wheat brought into the barn and then the weeds are burned (suggested as an action to be done since verb burn is expressed as an infinitive in the Greek: to be burned).
The Seventh parallel account details the end of the reign of the beast and reveals further information on a mystery. An angel from the bowls takes John aside and so changes the scene. The focus changes as well from detailing the unfolding of Gods plan to an explanation of the object of His wrath in threefold fashion, the Harlot, the Beast and Babylon. This provides detailed information that reveals some mysteries as is the nature of the book. This account runs through chapters 17 and 18; it literally describes the day and the hour of their destruction at the end of the seventieth seven from the sixth parallel account.
Chapter 19 marks a scene change back to the heavenly throne and the focus changes as well to Jesus now as conqueror going out to battle. Here Revelation reverts to a storyline linear fashion backing up into the seventieth seven to show how God is victorious and the conclusion of His plan of Salvation for the Christian. In sequential fashion, it moves into the time beyond the seventieth seven and as some would say for the first time in prophecy mentions the Millennial Period (although this period is covered by the Prophets both major and minor).