Revelation is the most misunderstood book of the Bible. When studying Revelation, there are many interpretations of each prophecy. How can we know which one is right? Prophecy is not a salvation issue but we are blessed when we live in confidence that God is sovereign and see His detailed plan for our world fulfilled. Revelation was written for Christians of the end of the End Times to understand and encourage once another.
 
Blessed is he that reads, and they that hear the words of this prophecy, and keep those things which are written therein: for the time is at hand (Revelation 1:3).

Some teachers say older traditional teachings are better than newer ones. All doctrines of the Bible were settled early but one. The Old Testament prophecies of Christ were better understood after the resurrection of Christ. The End Times is better understood the closer we get to the end of the Church Age. Because Israel became a nation in 1948 and Jerusalem its undivided capital in 1967, then other prophecies became clearer. A few prophecies have been fulfilled before the Tribulation begins.

He [angel] said unto me, Seal not the sayings of the prophecy of this book: for the time is at hand (Revelation 22:10).

Studying prophecy is a pursuit of truth. The Holy Spirit will teach all things. Follow proper Bible study. Reexamine long held traditions. Those who seek truth, will find it. Parts of Revelation are revealed and fulfilled now so people of the End Times strengthen their faith.

Knowing this first, that no prophecy of the scripture is of any private interpretation. For the prophecy came not in old time by the will of man: but holy men of God spoke as they were moved by the Holy Spirit (2 Peter 1:20-21)

7 Days, 7000 Years

Prophecy begins with time. God created the earth in six days and rested the seventh. The Millennial day theory states that creation is the pattern for God's time. Humanity rules six thousand years and then Jesus Christ rules a thousand years. Bible Chronology gives details that follow this millennial day timeline from Genesis to Revelation.

In six days the Lord made heaven and earth, the sea, and all that in them is, and rested the seventh day: wherefore the Lord blessed the sabbath day, and hallowed it (Exodus 20:11).

For a thousand years in thy sight are but as yesterday when it is past, and as a watch in the night (Psalm 90:4)

Beloved, be not ignorant of this one thing, that one day is with the Lord as a thousand years, and a thousand years as one day (2 Peter 3:8).

The genealogy from Adam to the flood is 1656 AM or years from creation (Genesis 5:1-32). Add 292 years to Abraham's birth or 1948 AM (Genesis 11:10-32). Abraham was 75 when God made a covenant (Genesis 12:1-2, 4). There are 430 years from the Abrahamic covenant to Mt. Sinai (Genesis 15:16, Exodus 12:41, Galatians 3:17). The Hebrews were enslaved in Egypt ~120 years. The Exodus is 2453 AM. Add 40 years in the wilderness and 5 years conquering the land. There are 480 years from Joshua as judge to Solomon's 4th year (1 Kings 6:1). Samson, Eli, Samuel, Saul and Philistines overlap. The first temple was built by Solomon in 2978 AM and lasted 410 years through the kings of Judah. In 3388 AM or 586 BC, the temple was destroyed by Babylon (2 Kings 25:8-9). Add 586 and 2021 then subtract 1. There is no year zero between BC and AD. The 1st of Tishri (September) is about 5994 AM. That is a good estimate of years from creation. There is a reason we are seeing so much prophecy fulfilled.

Calendars do not match God's time. The Jewish year 5781 is off by ~216 years. Add 5 years for Abraham, 40 years in the wilderness and 5 years of conquest. Jews count 490 years between destruction of the first and second temples but 586 BC to 70 AD is 656 years. Add 166 missing years for Persian and Greek rules of Judea. The Roman year is off by ~25 years. Most scholars believe Jesus was born before 1 BC. We are in the 21st century but not in the millennial reign of Christ. God's calendar counts from the cross and not Christ's birth.

Israel

There is a reason why so many prophecies are being fulfilled before the Tribulation. Israel is at the center of God's plan of redemption. What is the length of a generation? Some say forty years but the average lifespan is between seventy and eighty years. The generation that saw Israel become a nation will not pass away.

The days of our years are seventy years; and if by reason of strength they be eighty years, yet is their strength labor and sorrow; for it is soon cut off, and we fly away (Psalm 90:10).

When you shall see all these things, know that it is near, even at the doors. Verily I say unto you, This generation shall not pass, till all these things be fulfilled. (Matthew 24:33-34).

Seven Year Rapture Window

Jesus Christ was born ~7-1 BC and died ~27-33 AD, then ~2027-2033 could be the Second Coming of Jesus Christ. Subtract seven years and we are in a possible seven year rapture window of ~2019-2026 as God prepares the world for the seven years of Tribulation. Since we are at the end of the Church Age, watch Israel, China, the European Union, Russia and Iran prepare for the Tribulation. Most importantly, be awake and watch for Jesus to grab his people out of danger.

Knowing the time, that now it is high time to awake out of sleep: for now is our salvation nearer than when we believed (Romans 13:11).

Revelation can be understood through a proper study of Scripture. The millennium theory tells us we are near the end of the Church Age. Since we are so close to the Tribulation, are there any prophesies that have been fulfilled already? What do we see in the world preparing for the Tribulation?

References: 21st Century Revelation: World Wars, Iraq Wars & End Wars Chapter 5 - Study the Bible, Chapter 9 - In the Beginning, God, Chapter 10 - Seven Days of God, Chapter 16 - The Life of Christ, Chapter 17 - Basic Bible Chronology, Chapter 18 - Spring Forward or Fall Back, Revelation Outline, Timeline of the Tribulation, Tribulation, Revelation, Covenant, Chronology of Man, Jewish Chronology, HebCal Calendar, Millennial Day