Pat Harrington, Jr. played which character on the US TV sitcom "One Day at a Time"?

"One Day at a Time" is an American TV sitcom that aired on the CBS Network from December 1975, to May 1984. It starred Bonnie Franklin as a divorced mother raising two teenage daughters, played by Mackenzie Phillips and Valerie Bertinelli, in Indianapolis, Indiana. On this show, Pat Harrington Jr. playes Dwayne Schneider, a building superintendent who provides usually unwanted advice to the tenants, especially to the mother with the two teens.

The series "One Day at a Time" was created by Whitney Blake and Allan Manings, a husband-and-wife writing duo who had both been actors in the 1950s and 1960s. It was developed by Norman Lear and some of the directors include: Sandy Kenyon, Norman Campbell, Herbert Kenwith, Howard Morris, Noam Pitlik, Alan Rafkin, Don Richardson, and Tony Singletary.

The series was based on Blake's own life as a single mother raising her three children (including future actress Meredith Baxter) after her divorce from her first husband. The show ran for 9 seasons and produced 209 episodes. Stories depicting such events as weddings, births, and other important family and personal milestones were frequently stretched over two-, three-, and four-part episodes.