Taking C T Russell's calculations based on the Great Pyramid of Egypt out of the equation (that is a whole topic by itself......and YES......Russell believed that by adding up the dimensions of the Great Pyramid of Gizeh.......he could predict the future......which is....in and of itself......a spiritistic practice) we are left with the following:
Obviously we know they claim the fall of Jerusalem happened in 607 BC. They come up with that year based on 2 scriptures. One is found in Daniel Chapter 4 and is referring to the "seven times" representing Nebuchadnezzar. The "seven times" had an initial fulfillment during the reign of Nebuchadnezzar when he went insane and lived among the beasts of the fields for 7 years. But the society says that this prophecy has a greater fulfillment and that greater fulfillment happened from the period of time of Jerusalem's destruction (which is placed at 607BC) down to the end of the Gentile Times. The "seven times" are interpreted as 7 lunar years with each year consisting of 360 days. That gives us 2,520 days. However, other prophecies are then referred to, using the expression "day for a year". Employing this formula, 2,520 days becomes 2,520 years. 2,520 years from 607 BC takes us forward to 1914. There are two points of interest here. One is that the society claims that although the book of Daniel has many prophesies (2 nd , 4 th , 5 th , 7 th , 9 th and 11 th chapters)….only the 4 th chapter contains 2 fulfillments. The other point of interest is that the 2,520 years is calculated using lunar years of 360 days each. But…..when starting at 607BC and counting forward into the future…..the society uses SOLAR years of 365 ¼ days to actually apply the prophecy. Why the discrepancy? Why use lunar years to calculate but solar years to apply?
The other main scripture the society focuses on refers to the 70 years of desolation. According to the Society, Jeremiah, in his 25th Chapter predicts that Jerusalem would be desolated for 70 years. From Cyrus' decree for the Jews to return to their homeland (which JWs have dated as 537BC) and going back 70 years, you come up with 607 BC as the fall of Jerusalem. This is an all important date for Jehovah's Witnesses. Present teachings about the beginning of Christ's kingdom rule, the last days, when the resurrection would begin etc etc are all tied in with this calculation. Not many Witnesses can explain the intricate application and combination of texts involved, but they accept the end product of this process. The problem is that there is NO historical evidence to back up the idea that Jerusalem fell in 607 BC. Acknowledging this, many witnesses will say this may be true, but when it comes to trusting history vs God's Holy word, they put their trust in God. That seems like the correct thing to say. I said it for many years. But then I got to looking at all the evidence against 607 BC. When I looked at all of it, I thought to myself "is this really historical evidence vs the bible?" I determined that is not the case. This is a matter of historical evidence vs the Watchtower Society's doctrine and chronology. The Society's best written argument against 586/587 BC is found in the Kingdom Come book Appendix to Chapter 14. When proper research is done.......their arguments are found to be paper thin.