It was about the year 1969 with the release of the book " Life Everlasting In Freedom Of The Son Of God" { " Life Everlasting" } book that stated in that publication that 6000 years of human history would culminate in the year 1975 in October.
I was 30 years old at the time and I had reservations about it.The G.B. at the time also stated that it the big "A" might even happen sooner or a bit later , however not years later maybe only a few months later because of not knowing when Eve was created.