This is in relation to Daniel's prophecy of 70 "sevens", not, I believe, the Biblical length of generations.
I’m just commenting on the fact that end times prognosticators were almost all in agreement that a generation was 40 years, until 1988 rolled around and their prognostications failed to come true. Then they either decided a generation must be 70 years, or they needed to start the 40 year count from 1967.
When they are all wrong in 2017/2018, I expect them all to agree that a generation must be 70 years AND the counting must start in 1967, and that will give them until 2037 to make more bad predictions.