Up until 1970 the WTS taught that the GT started 1914 and was temporarily interrupted in 1918 to start up again at a future date (1925-1970)
*** w99 5/1 pp. 16-17 pars. 10-13 “Let the Reader Use Discernment” ***
10 God’s people once understood that the first phase of the great tribulation began in 1914 and that the final part would come at the battle of Armageddon. (Revelation 16:14, 16; compare The Watchtower, April 1, 1939, page 110.) So we can understand why it was once thought that the latter-day “disgusting thing” must have stood in a holy place soon after World War I.
11 However, in later years we have come to see things differently. On Thursday, July 10, 1969, at the “Peace on Earth” International Assembly in New York City, F. W. Franz, then vice president of the Watch Tower Bible and Tract Society, gave an electrifying talk. In reviewing the previous understanding of Jesus’ prophecy, Brother Franz said: “The explanation was given that the ‘great tribulation’ had begun in 1914 C.E. and that it was not allowed to run its full course then but God stopped World War I in November of 1918. From then on God was allowing an interval for the activity of his anointed remnant of elect Christians before he let the final part of the ‘great tribulation’ resume at the battle of Armageddon.”
12 Then a significantly adjusted explanation was offered: “To correspond with the events of the first century, . . . the antitypical ‘great tribulation’ did not begin in 1914 C.E. Rather, what took place upon Jerusalem’s modern antitype in 1914-1918 was merely ‘a beginning of pangs of distress’ . . . The ‘great tribulation’ such as will not occur again is yet ahead, for it means the destruction of the world empire of false religion (including Christendom) followed by the ‘war of the great day of God the Almighty’ at Armageddon.” This meant that the entire great tribulation was yet ahead.
13 This has a direct bearing on discerning when “the disgusting thing” stands in a holy place. Recall what happened in the first century. The Romans attacked Jerusalem in 66 C.E., but they abruptly withdrew, which allowed Christian “flesh” to be saved. (Matthew 24:22) Accordingly, we expect the great tribulation to begin soon, but it will be cut short for the sake of God’s chosen ones. Note this key point: In the ancient pattern, ‘the disgusting thing standing in a holy place’ was linked to the Roman attack under General Gallus in 66 C.E. The modern-day parallel to that attack—the outbreak of the great tribulation—is still ahead. So “the disgusting thing that causes desolation,” which has existed since 1919, apparently is yet to stand in a holy place. How will this happen? And how can we be affected?