Few more teasers:
'What about the year 1975? What is it going to mean, dear friends?' asked Brother Franz. 'Does it mean that Armageddon is going to be finished, with Satan bound, by 1975? It could! It could! All things are possible with God. Does it mean that Babylon the Great is going to go down by 1975? It could.'
Kingdom Ministry, 3/68, p. 4 "...there are only about ninety months left before 6000 years of man's existence on earth is completed.... The majority of people living today will probably be alive when Armageddon breaks out, and there are no resurrection hopes for those who are destroyed then."
Kingdom Ministry, 6/69, p. 3 "In view of the short time left, a decision to pursue a career in this system of things is not only unwise but extremely dangerous."
The Nations Shall Know that I am Jehovah—How? 1971 p.216. “Shortly, within our twentieth century, the "battle in the day of Jehovah" will begin against the modern antitype of Jerusalem, Christendom."
.
Then there was the change to having a six-month study with interested persons, since any more than that was a waste of the ever decreasing time left:
*** w69 5/15 p. 312 Have You Been Studying for Six Months? ***
In view of the short time left in which to do their work, Jehovah’s witnesses do not continue to study the Bible with any who fail to respond to its urgent message within six months. The nearness of this system’s end compels them to use their time in the most effective way possible. So they feel obligated to spend their time calling on someone else who might respond by attending meetings at the Kingdom Hall and by speaking to others about the Bible truths learned. Thus it may be that if you have not as yet responded by even becoming a regular attender at some of the congregation meetings, the one who is studying the Bible with you may cancel that study arrangement in order to give his time to someone else. This arrangement is not meant to be harsh, but the urgency of the times in which we live demands it.