When I was a kid, the doomsday year was 1981. You see, Jesus said that the generation that “witnessed the budding of the fig tree” would be the generation to see the Lord’s return. The budding of the fig tree was the birth of the nation Israel, which happened in 1948. According to the Bible, a generation of judgment is 40 years, but within that time, Jesus will come back and call up his church, leaving the rest of mankind in Tribulation for another seven years. So, 1948 plus 40 equals 1988. But subtract the seven-year Tribulation, and what do you have? 1981.
Hal Lindsay made a lot of dough with this equation.