Here's a quote from the JWs from 1966:<quoted text>
I wouldn't have to manage my anger if psople (like you) would manage their stupidity!
They never said the end would come in 1975! They said it COULD come in 1975. It COULD come tomorrow! Now what false reasonong do you have to complain about that?
It is you who is trying to peddle----!You have been mislead by drinking the Devil's brew! You know it is not good as is but you chose to drink it anyway
"The published timetable resulting from this independent study gives the date of man's creation as 4026 B.C.E. According to this trustworthy Bible chronology six thousand years from man's creation will end in 1975, and the seventh period of a thousand years of human history will begin in the fall of 1975 C.E. So six thousand years of man's existence on earth will soon be up, yes, within this generation. So in not many years within our own generation we are reaching what Jehovah God could view as the seventh day of man's existence. How appropriate it would be for Jehovah God to make of this coming seventh period of a thousand years a sabbath period of rest and release, a great Jubilee sabbath for the proclaiming of liberty throughout the earth to all its inhabitants! This would be most timely for mankind. It would also be most fitting on God's part, for, remember, mankind has yet ahead of it what the last book of the Holy Bible speaks of as the reign of Jesus Christ over earth for a thousand years, the millennial reign of Christ. It would not be by mere chance or accident but would be according to the loving purpose of Jehovah God for the reign of Jesus Christ, the 'Lord of the Sabbath,' to run parallel with the seventh millennium of man's existence." Life Everlasting in Freedom of the Sons of God 1966 pp.26-30
Notice they say 1975 pretty clearly.
This page has a bunch of data on the 1975 prediction:
The only way you can reject this information and say that they never predicted the end of the world is to completely isolate yourself from the world outside the Watchtower.
And that is exactly what a cult would want you to do. Think about it.