Which was the last NHL arena to retain the use of an analog dial-type large four-sided clock for timekeeping?

Chicago Stadium was an indoor arena located in Chicago. It opened in 1929, and closed in 1994. The Stadium hosted the Chicago Blackhawks of the NHL from 1929–1994 and the Chicago Bulls of the NBA from 1967–1994.

Chicargo Stadium was the last NHL arena to retain the use of an analog dial-type large four-sided clock for timekeeping in professional hockey games. Boston Garden and the Detroit Olympia (as well as the Buffalo Memorial Auditorium in its pre-NHL days) had identical scoreboards but replaced them with digital timers in the mid-1960s, with Boston having their digital four-sided clock in use for the 1969–70 NHL season. Built by Bulova as their "Sports Timer", and installed in Chicago in 1943, each side of the clock had a large diameter 20-minute face in the center that kept the main game time for one period of ice hockey, with a set of shorter black-colored minute and longer red-colored sweep-second hands, and a pair of smaller, 5-minute capacity dual-concentric faces for penalty timekeeping.