Television seasons: when do they begin? And when do they end? Does anybody really care anymore?

Can we have a show of hands from folks who will really stop what they’re doing and plan their night around tonight’s season finale of “Scrubs” (8:30 p.m., NBC)? Were you anticipating the finales of “Whoopi”? “Happy Family”? “I’m With Her”? “It’s All Relative”? “Married to the Kellys”? If so, you missed them.

The last “Scrubs” of the season is particularly hard to get excited about since the comedy and its characters exude apathy and a couldn’t-be-bothered attitude. If they don’t care about what they’re doing (J.D. pursuing Elliot until Elliot submits), or saying (J.D. admitting that now that he has Elliot he doesn’t want her), why should we? For those who do care, tonight is Turk and Carla’s wedding. Expect wackiness.

Tonight’s other highlights

• On three consecutive episodes of “Frasier” (NBC): matchmaking (7 p.m.), a sudden crush (7:30 p.m.), kitchenware-induced nostalgia (8 p.m.).
• The final five sing to survive on “American Idol” (7 p.m., Fox).
• Luke suddenly realizes his one true love on “Gilmore Girls” (7 p.m., WB). Well, duh!
• Nick takes a job with the competition on “The Guardian” (8 p.m., CBS).
• Tony’s fateful decision on “24” (8 p.m., Fox).
• A serial killer targets the geriatric set on “Law & Order: Special Victims Unit” (10 p.m., NBC).
• Andy’s chief suspect is found slain on “NYPD Blue” (9 p.m., ABC).

Late night

Mary-Kate and Ashley Olsen and Adam Brody appear on “Late Show with David Letterman” (10:35 p.m., CBS) … Jay Leno welcomes Eric Bana, Bob Woodward and Lee Ann Womack on “The Tonight Show” (10:35 p.m., NBC) … Jamie Foxx and Constance Marie appear on “Jimmy Kimmel Live” (11:05 p.m., ABC).

Ray Liotta, Mila Kunis and Carly Simon are booked on “Late Night with Conan O’Brien” (11:35 p.m., NBC) … Jane Leeves and Crystal Method appear on “The Late, Late Show with Craig Kilborn” (11:37 p.m., CBS).