January 14, 1968
Episode 1 of Season 21 premiered on January 14, 1968
July 21, 1968
Episode 2 of Season 21 premiered on July 21, 1968
August 25, 1968
Episode 3 of Season 21 premiered on August 25, 1968
September 29, 1968
Episode 4 of Season 21 premiered on September 29, 1968
November 10, 1968
Episode 5 of Season 21 premiered on November 10, 1968