As the shopping days dwindle down, everybody’s throwing a marathon. You get the impression that the programming departments just want to let the shows rip while they sip eggnog and unwrap presents. Who can blame them?

• The Cartoon Network kicks off its animated marathon early, with “Olive the Other Reindeer” (8 a.m.), a clever Christmas fable produced by the folks behind “The Simpsons,” featuring the voice of Drew Barrymore. Other holiday classics include “‘Tis the Season to Be Smurfy” (10 a.m.), “The Smurfs Christmas Special” (10:30 a.m.) and “How the Grinch Stole Christmas” (12:30 p.m.).
• MTV offers five solid hours of “Newlyweds” (5 p.m., MTV), the excruciating slice-of-life series featuring married pop singers Jessica Simpson and Nick Lachey. Relive the times Jessica risked death to bring her food-filled Louis Vuitton handbag (“Little Louis”) into her tent in a bear-infested campground, promulgated her complicated theories about women’s golf, and pondered the ravages of advancing years.
• Showtime offers 10 consecutive episodes of “Penn & Teller: Bull!” (7 p.m., Showtime). This funny, in-your-face topical series is definitely worth catching. The illusionists offer scathing assessments of popular delusions and outright scams including TV mediums, alien abductions, bottled water, second-hand smoke and other controversial topics. Caution: Penn gets rather heated at times and his language may be too strong for some. That’s why the real title of the show can’t be printed in a family newspaper.

Tonight’s other highlights

• Kelly Diedring, the winner of the “King of the Jungle” (7 p.m., Animal Planet) contest, gets to host her own hourlong special.
• Take-your-son-to-work day on “Everybody Loves Raymond” (8 p.m., CBS).
• Danny McCoy (Josh Duhamel) has a fling with the boss’s daughter on the series pilot of “Las Vegas” (8 p.m., NBC). Danny hunts for his pal’s killers in a second episode (10 p.m.).
• Oakland is host to Green Bay on “Monday Night Football” (8 p.m., ABC).
• Tenor Andrea Bocelli sings “Sacred Arias” and other Christmas carols on “Great Performances” (8 p.m., PBS, check local listings).
• Liza Minnelli and Henry Winkler guest star on “Arrested Development” (8:30 p.m., Fox).
• Death takes a time-share on “CSI: Miami” (9 p.m., CBS).

Late night

Steve Martin appears on “Late Show with David Letterman” (10:35 p.m., CBS) … Jay Leno greets Jessica Alba, Peter and Bobby Farrelly, and the Brian Setzer Orchestra on “The Tonight Show” (10:35 p.m., NBC).