I Am Britney Jean: An intimate look at pop icon Britney Spears before she embarks on a two-year Las Vegas residency. (Michelangelo Di Battista/Photo courtesy of RCA Records, a division of Sony Music Entertainment)

Based on previously published comic strips from Charles M. Schulz, “I Want a Dog for Christmas, Charlie Brown” (ABC at 8 p.m. Saturday) has Linus and Lucy’s little brother, ReRun, hanging out with Snoopy and Spike to avoid the Van Pelt holiday chaos.

“The Christmas Blessing” (Hallmark at 8), a sequel to the 2002 film “The Christmas Shoes,” has Nathan Andrews, the boy in the original film, all grown up with a doctorate degree, but his life suddenly shifts when he returns to his home town during the holidays and finds love. Stars Neil Patrick Harris, Rebecca Gayheart, Angus T. Jones and Rob Lowe.

Jimmy Fallon returns to host “SNL” (NBC at 11:30) with musical guest and frequent host Justin Timberlake.

Sunday talk shows: “Platts Energy Week” (WUSA at 7:30 a.m.) interviews energy secretary Ernest Moniz; “This Week in Defense News” (WUSA at 8) has the American Enterprise Institute’s Mackenzie Eaglen;“BioCentury This Week” (WUSA at 8:30) features BioCentury’s Steve Usdin; “Fox News Sunday” (Fox at 9) hosts former Arkansas governor Mike Huckabee (R) and pastor Joel Osteen; “White House Chronicle” (WETA at 9) has risk consultant David Ropeik; “State of the Union” (CNN at 9) features Sen. Joe Manchin (D-W.V.) and Reps. Tulsi Gabbard (D-Hawaii) and Aaron Schock (R-Ill.).

“Government Matters” (WJLA at 9:30) hosts the Washington Business Journal’s Jill Aitoro and Washington Technology’s Nick Wakeman; “This Week” (ABC at 10) features Rep. Mike Rogers (R-Mich.) and Sen. Mark Udall (D-Colo.); “Newsmakers” (C-SPAN at 10) talks to Sen. David Vitter (R-La.); “This Is America & the World” (WETA at 10 and WHUT at 6 p.m.) talks to students, faculty and staff from Kazakhstan’s Nazarbayev University; “Meet the Press” (NBC at 10:30) has Sens. Chuck Schumer (D-N.Y.) and Tom Coburn (R-Okla.); “Face the Nation” (CBS at 10:30) talks to former CIA director Michael Morell.

Sunday night, “I Am Britney Jean” (E! at 9 p.m.) follows pop icon Britney Spears as she prepares for a two-year Las Vegas residency and the release of an album. The documentary will offer a glimpse into her personal and professional life with intimate interviews and behind-the-scenes footage.

Oprah Winfrey checks in with “Beverly Hills, 90210” star Ian Ziering, Ivana Trump and “Project Runway” winner Christian Siriano on the latest episode of “Oprah: Where Are They Now?” (OWN at 10).

— Rachel Lubitz