I came here to quote the very magazine that bennyk did. They made the original OP's article believing they were creating rules that would eliminate the possibility of being false prophets. What they didn't know is they already broke those rules in the May 15, 1984 Watchtower.
Jehovah's prophetic word through Christ Jesus is: 'This generation [of 1914] will by no means pass away until all things occur.' (Luke 21:32) And Jehovah, who is the source of inspired and unfailing prophecy, will bring about the fulfillment of his Son's words in a relatively short time." (Watchtower 15. MAY 1984, p. 6 [brackets theirs!])