Here's the pertinent section.....
HAVE JEHOVAH’S WITNESSES GIVEN INCORRECT DATES FOR THE END?
Jehovah’s Witnesses have had wrong expectations about when the end would come. Like Jesus’ first-century disciples, we have sometimes looked forward to the fulfillment of prophecy ahead of God’s timetable. (Luke 19:11; Acts 1:6; 2 Thessalonians 2:1, 2) We agree with the sentiment of longtime Witness A. H. Macmillan, who said: “I learned that we should admit our mistakes and continue searching God’s Word for more enlightenment.”
Why, then, do we continue to highlight the nearness of the end? Because we take seriously Jesus’ words: “Keep looking, keep awake.” The alternative, to be found “sleeping” by Jesus, would prevent us from gaining his favor. (Mark 13:33, 36) Why?
Consider this example: A lookout in a fire tower might see what he thinks is a wisp of smoke on the horizon and sound what proves to be a false alarm. Later, though, his alertness could save lives.
Likewise, we have had some wrong expectations about the end. But we are more concerned with obeying Jesus and saving lives than with avoiding criticism. Jesus’ command to “give a thorough witness” compels us to warn others about the end.—Acts 10:42.
We believe that even more important than focusing on when the end will come, we must be confident that it will come, and we must act accordingly. We take seriously the words of Habakkuk 2:3, which says: “Even if [the end] should delay [compared to what you thought], keep in expectation of it; for it will without fail come true. It will not be late.”