Known for he consistently cheery demeanor, Clarence Day was given the nickname “Happy” before having it shortened to “Hap”. After playing impressively for the Hamilton Tigers of the OHA Sr. league in his early 20s, Day caught the attention of the Toronto St. Pats brass and was offered a contract. Day began his career in Toronto as a winger in the 1924-25 season, but would move back to defense for the remainder of his career the following season. In Day’s sophomore season, he would lead all defensemen with 16 points and a dominating 14 goals, four goals ahead of the nearest competition.
After another strong season, Day was named the team captain in 1927 at the age of 26 years old. Day would have an extremely strong 1927-28 season, tying for the league lead in points among defensemen with Eddie Shore and Lionel Conacher, but doing it in many less games; 17 points in just 22 games. Day’s season was shortened due to an injury to his Achilles heel that he failed to let heal completely the first time through. Day managed to play every game of the 1928-29 season, however, and led all Leafs defenders in points, finishing 4th in the league.
Day’s leadership continued for the Leafs, eventually leading to a Stanley Cup in 1932, the first in Leafs history. Day paired up with King Clancy to create one of the strongest pairs in the NHL. The Leafs dominated in the 1930s, largely due to their dominant first line, but also due to the consistent play of Clancy and Day, with Clancy usually playing the more offensive role.
Unlike many players of the era, Day was able to play well into his 30s and continually played almost every game of the season until he went to the New York Americans for the 1937-38 season. Even there, Day played 43 of a possible 48 games. Day retired after that one season in New York at the age of 36. Day retired at 3rd all-time in assists and 2nd in games among defensemen, cementing his legacy. He also retired as the longest tenured Leafs captain, a mark that would not be surpassed until the great Mats Sundin.
Three seasons after retiring as a player, Day took to the bench as the head coach for the Toronto Maple Leafs, where he would spend the next 10 years. Unlike many players-turned-coaches, Day would have great success as a bench boss, leading the Leafs to five Stanley Cups in the 40s, including three consecutive ones in the late 40s. In 1942, Day coached the first reverse sweep in a 7-game series in Stanley Cup history, when the Leafs came back from a 3-0 game deficit to win four straight and their second Stanley Cup.
In the 50s, Day would serve as an assistant general manager and a general manager for one season as well. Day was inducted into the Hockey Hall of Fame in 1961 and his No. 4 is retired for both him and Red Kelly by the Toronto Maple Leafs.