Harry Potter movie marathon (9am, ABC Family) - ABC Family is airing an all-day marathon of Harry Potter movies, beginning at 9am with "Harry Potter and the Sorcerer's Stone." "Harry Potter and the Chamber of Secrets" follows at 12:30pm, and then "Harry Potter and the Prisoner of Azkaban" at 4:30pm, and "Harry Potter and the Goblet of Fire" at 7:30.
Battlestar Galactica (7pm, BBC America) - President Roslin questions the judgement of Adama and Apollo when they put the fleet at risk to find Starbuck, whose Viper disappeared after a run-in with a Cylon patrol. A second episode airs at 8.
Dino Gangs (8pm, Discovery) - The remains of 68 Tyrannosaurus rexes are recovered in the Gobi Desert, and research suggests that the species may have been deadlier than previously thought.
A Fairly Odd Movie: Grow Up, Timmy Turner! (8pm, Nick) - A live-action version of the cartoon "The Fairly OddParents" finds 23-year-old Timmy (Drake Bell) wanting to remain a kid forever so he can hold on to his fairy godparents. However, he considers changing his mind when a grown-up Tootie returns to town.
Carson Nation (10pm, OWN) - Carson travels to Scottsdale, Arizona, where he helps a transgender woman who has lived as a man for 60 years.