Some decades back, a name-brand household cleanser had an advertising mascot named Josephine the Plumber, played by actress Jane Withers. She was spunky, pretty and dressed in overalls – a shocking sight even for viewers used to the absurd shenanigans on “Bewitched” and “I Dream of Jeannie.” Given the social attitudes expressed on television at the time, there was something almost out of this world about the idea of a woman plumber. It was as fantastic as being visited by the earring-ed Mr. Clean or having a chat with that Tidy Bowl guy floating in a boat in the back of your, er, water closet.

Times have changed. Or maybe they haven’t. “Toolbelt Diva” (8 p.m., Discovery Home) enters its second season, starring loud-and-proud handywoman Norma Vally, who teaches other women not to be squeamish about minor plumbing jobs, replacing decks, pulling up floors and other messy household chores.

In tonight’s installment, a new Seattle homeowner learns how to replace a kitchen sink, faucet and garbage disposal that all appear to be much older than her 9-year-old home.

¢ “Class of 1990” (7 p.m., CMT) glances back at the music, marriages, gossip and breakthroughs in country music during the year that The Judds, George Strait, Reba McEntire, Randy Travis and Garth Brooks dominated the charts.

¢ Despite everything we’ve learned from Warner Bros. cartoons, the Tasmanian devil isn’t all that ornery. “Terrors of Tasmania” (7 p.m., National Geographic) follows the meat-eating marsupial across the terrain of its island home.

Tonight’s other highlights

¢ A cranky student (Hilary Duff) becomes clingy after Joan saves her life on “Joan of Arcadia” (7 p.m., CBS).

¢ Scheduled on “Dateline” (7 p.m., NBC): the 2004 terror attack in Madrid; an interview with Kelly Clarkson.

¢ A posh Malibu pad pushes a teen (Leelee Sobieski) to a jagged edge in the 2001 thriller “The Glass House” (7 p.m., Fox).

¢ Cuba Gooding Jr. and Skeet Ulrich star in the 1999 thriller “Chill Factor” (7 p.m., UPN).

¢ Dr. Joyce Brothers guest stars on “JAG” (9 p.m., CBS).

¢ Evidence of an engineering student’s suicide just doesn’t add up on “Numb3rs” (10 p.m., CBS).

¢ Scheduled on “20/20” (9 p.m., ABC): a model discusses her father’s gambling addiction; an interview with Osama Bin Laden’s niece.