Luke 21:24
Luke 21:2424They will fall by the edge of the sword and be led captive into all the nations. And Jerusalem will be trodden down by the Gentiles, until the times of the Gentiles are fulfilled.
One of the load-bearing texts for 1914. The Watchtower links "the appointed times of the nations" to the "seven times" of Daniel 4, converts those into 2,520 years, and counts from a Jerusalem destruction dated to 607 BCE — arriving at 1914 as the year Christ began ruling invisibly and the last days began. The 1919 appointment of the faithful and discreet slave follows from it. For many Witnesses this chronology is among the strongest evidences that Jehovah is directing the organisation.
You do not need to fight about 607 BCE, and it is usually a mistake to try. The chronology is a chain with several links, and arguing any one of them invites a rehearsed answer. The shorter route is the one Russell himself supplies. In Studies in the Scriptures — the book that established this chronology — he wrote that the reader "must not expect to have passages of Scripture pointed out in which these matters and dates are plainly written," because they had been hidden by the Lord until the due time and revealed only to his faithful children. Read that aloud and ask three questions. What kind of proof is being offered? Is a claim that the meaning was hidden until the right interpreter arrived a falsifiable claim, or one that validates whoever makes it? And would the same paragraph be accepted from another movement's founder with the dates changed? Then : not even the Son knows the day or hour. Russell could not point to passages because the passages are not there. Compare , , .