Tuesday Comic Strip Day.
Frank Johnson was a long time Mort Walker assistant who took over the drawing of Boner's Ark after Walker himself left the strip (in the early seventies, I guess). I think you can see the change after 1969, as I will show below. Around that same time he also had his own weekly fill-in strip in the New York Sunday paper, which used all sorts of specially made strips as filler material. Later Johnson took over the inking of Dik Browne's Hi and Lois, although that may have been after Browne died. Mort Walker once told me a salty anecdote about Johnstone telling him 'he loved Dik'.