I had a friend in college who, if given any date in history, could tell you what day of the week that date fell on. I used the perpetual calendar from my trusty World Almanac to check him and he was always right. Example, I’d say, “August 12, 1821.” He’d pause a second or two and say, “Sunday.” Said it was a pretty simple formula, and he taught it to me but I’ve long since forgotten.
This was a trick that the real “Rain Man” could do also, as he proved in an interview with Morley Safer on “60 Minutes” some years ago. (Morley held the World Almanac on him too.)
Can anybody teach me how to do this truly MP trick?