I once had a sister tell me (some time in the 90's) that she thought Armageddon would come in 2005.
Apparently, through some convoluted calculations based on something in the old "Aid" book, she determined that Adam was about 30 years old when Cain was born. To this JW, that meant that Eve was created when Adam was 30 also (I know I know) and since 6000 years since Adam's creation ended in 1975, then 6000 years since Eve's creation would run out in 2005.
Oh, and if you ask any JW at any point in time "when do you think Armageddon is coming", the answer will inevitably be "oh, this old system can't last more than 5 more years".
Maybe that's why Armageddon never comes - it's always "5 years away".