But seriously, I believe there's a Questions From Readers
It's the Watchtower 1972 6/1 p.352:
● Why did the beginning of World War I not coincide with the early part of October, when the “appointed times of the nations” ended?—U.S.A.
As has often been shown in this magazine, the conferring of kingship over the nations on Christ Jesus took place in 1914 C.E., at the expiration of the “appointed times of the nations” or the Gentile Times. (Luke 21:24; Dan. 4:16, 17, 31, 32) Those “appointed times” began 2,520 years earlier, after the destruction of Jerusalem in 607 B.C.E. and the assassination of the Jewish governor Gedaliah. The murder of Gedaliah in the month of Tishri (September/October) (“at the seventh new moon,” Byington translation) prompted those Jews left remaining in the land of Judah to flee. (Jer. 41:1, 2; 43:2-7) By the time the fearful Jews fled to Egypt it must have been at least the middle of Tishri, to allow enough time for the events mentioned in the Bible as taking place between the assassination and the flight. (Compare Jeremiah 41:4, 10–42:7.) This would place the start of the Gentile Times about Tishri 15, 607 B.C.E.
At the end of the Gentile Times, about Tishri 15 (October 4/5), 1914 C.E., Revelation 11:15 was fulfilled: “The kingdom of the world did become the kingdom of our Lord and of his Christ.” By enthroning his Son Jesus Christ, Jehovah God took his power to rule as King over the world of mankind. The rulership of the great Adversary, Satan the Devil, was due to end.
Being the ‘ruler of the world’ of mankind alienated from God, Satan certainly did not want to see the Kingdom take full control of earth’s affairs. (John 12:31; 14:30; 16:11) Over nineteen centuries earlier he maneuvered matters in such a way that, had it not been for divine intervention, Herod the Great would have killed the infant Jesus. (Matt. 2:13) Similarly, even before the birth of the heavenly kingdom, Satan readied himself and his demons for an attack. This is symbolically described at Revelation 12:3-5, where we read: “Another sign was seen in heaven, and, look! a great fiery-colored dragon, with seven heads and ten horns and upon its heads seven diadems; and its tail drags a third of the stars of heaven, and it hurled them down to the earth. And the dragon kept standing before the woman who was about to give birth, that, when she did give birth, it might devour her child. And she gave birth to a son, a male, who is to shepherd all the nations with an iron rod. And her child was caught away to God and to his throne.”
It should not be surprising, then, that World War I broke out about two months before the end of the Gentile Times, and hence before the birth of the symbolic “son” or heavenly kingdom. Satan the Devil did not need to wait until after kingship over the nations had been placed in the hands of Jesus Christ to maneuver the nations into a large-scale war. The start of that sanguinary conflict was doubtless part of his scheme to blind persons to what had happened in the heavens in fulfillment of Bible prophecy and also, if at all possible, to hinder the Kingdom from ruling over the world of mankind.