1) From The Watchtower, October 15, 1969, pages 622-3
"More recently earnest researchers of the Holy Bible have made a recheck of its chronology. According to their calculations the six millenniums of mankind's life on earth would end in the mid-seventies."
2) From “Our Kingdom Ministry, May, 1974, page 3:
“Yes, the end of this system is so very near! Is that not reason to increase our activity? In this regard we can learn something from a runner who puts on a final burst of speed near the finish of a race. Look at Jesus, who apparently stepped up his activity during his final days on earth. In fact, over 27 percent of the material in the Gospels is devoted to just the last week of Jesus’ earthly ministry!—Matt. 21:1–27:50; Mark 11:1–15:37; Luke 19:29–23:46; John 11:55–19:30."