The Simpsons. As part of the kickoff for its 30th season celebration, the show reruns its first full-length episode, “Simpsons Roasting on an Open Fire,” which originally aired on Dec. 17, 1989. 8 p.m. Sunday, Dec. 23, Fox.

Madam Secretary. Note the earlier time slot for the first installment of a two-parter in which Secretary of State Elizabeth McCord (Téa Leoni) takes on a governor whose state has started separating unauthorized immigrants from their children. Second installment airs Jan. 6. 8:30 p.m. Sunday, Dec. 23, CBS.

It’s a Wonderful Life. If you can’t imagine the holidays without an angel named Clarence and a gym floor that opens over a swimming pool, NBC has you covered on Christmas Eve. 8 p.m. Monday, Dec. 24, NBC.

Die Hard Christmas Marathon. Is Die Hard a Christmas movie? The Goldbergs say it is, and so does IFC, which will be rerunning it from Christmas afternoon through to midnight. (Start early and you can catch Live Free or Die Hard at 3:30 a.m. or 9:15 a.m. and Die Hard With a Vengeance at 6:30 a.m. and 12:15 p.m.) Yippee ki-yay! 3 p.m. Tuesday, Dec. 25, IFC.

The 41st Annual Kennedy Center Honors. This year’s honorees include Cher, Philip Glass, Reba McEntire, Wayne Shorter, and the four cocreators of the Broadway hit Hamilton, including Lin-Manuel Miranda, Andy Blankenbuehler, Thomas Kail, and Alex Lacamoire. 8 p.m. Wednesday, Dec. 26, CBS.