Corsi's article (in WND). He uses that date specifically and then others have picked it up.
But it's just dead wrong. I was on the University of Washington campus almost every day between around 10 August and around 15 September in 1961. There weren't any classes in process and there wasn't any real physical attendance anywhere either.
Could the August 19 have been a registration date for extension courses or correspondance courses? They wouldn’t necessarily follow the same schedule as regular classes. At least, they didn’t at Berkeley. I thought it might be necessary for me to take a correspondance course one summer when I was at Berkeley during that same time period.
I remember that I had to apply for permission to do so — done by mail. After I was approved, I had to come up with tuition, send for materials, etc. As it turned out, I didn’t take the course, after all, but that was the procedure.