Career
A defensive end, he played college football at North Carolina A&T State University, and professionally in the American Football League for the Buffalo Bills and the San Diego Chargers. He was part of the Bills" defense, which did not allow a rushing touchdown for 17 consecutive games over a portion of the 1964 and 1965 seasons, winning the American Football League Championship in both years. Day was an American Federation of Labor-Congress All-Star in 1965.
Day said of winning the American Federation of Labor-Congress championship, "Winning the championship is like making love to the most beautiful woman in the world.".