I recently completed a study of presidential count-back dates. In the study, I took the time that elapsed between a president and his first taking office and then counted backward from the president’s birth using that time. My survey only covered the 21 presidents whose count-back dates land after the inauguration of George Washington. I was curious what the earliest presidential count-back date would be absent that restriction. In a post at NAF Musings, I determined that the president with the earliest count-back date was John Adams, posting June 27, 1674. While there was obviously no U.S. President on June 27, 1674, John Adams’ count-back King was Charles II.