Even the most forgettable Christmas movie says something about the time in which it was made. Long before the real estate bubble burst, Kelsey Grammer starred in the fascinatingly preposterous 2002 TV movie “Mr. St. Nick” (7 p.m., today, Hallmark). He plays the spoilt heir to Santa Claus (Charles Durning) due to inherit the family business and extensive Christmas Eve obligations. But this young Claus would rather hang out in Miami Beach soaking up the sun and ogling bikini-clad women.

Like many a wayward Christmas carol, too many subplots lead this tale astray. Nick the younger falls for a gold-digging TV meteorologist (Elaine Hendrix) who bamboozles him into participating in a dot-com fraud. How early 21st century! Fortunately, he has a feisty, faithful chef (Ana Ortiz) who sees through his weather girl’s fraudulent plans. As overstuffed as an unwanted fruitcake, this far-fetched Christmas movie affords Grammer plenty of chances to strut his stuff as a delusional bon-vivant, a character not all that different than his signature role on “Frasier.”

Other too-early holiday movies include “Once Upon a Christmas” (7 p.m., today, Family), followed by “Twice Upon a Christmas” (9 p.m.). In these two, Kathy Ireland plays Santa’s daughter.

• Divas reign as Janet Jackson offers the opening performance of the 37th annual American Music Awards (7 p.m., Sunday, ABC), the same ceremony that will bestow a special International Artist Award on Whitney Houston, who will also perform live. Jackson’s late brother, Michael, leads the list of the most-nominated, along with Eminem and Taylor Swift.

• On the 46th anniversary of President Kennedy’s assassination, Discovery offers two documentaries rehashing long-established theories and persistent questions about one school of conspiracy theory. “Did the Mob Kill JFK?” (7 p.m., Sunday, Discovery) examines claims by then jailed New Orleans mob boss Carlos Marcello that he had the president eliminated to end Attorney General Robert Kennedy’s war on organized crime. The documentary also recalls links between the Kennedy family and organized crime and the CIA’s use of Mafia hit men to try and kill or overthrow Cuban communist dictator Fidel Castro.

“JFK: The Ruby Connection” (8 p.m.) examines the peculiar life-and-death story of the man who shot Lee Harvey Oswald and examines stories of his alleged connections to the mob and possible prior connections to the man he would shoot on live television.

Today’s highlights

• Tyler Florence hosts “All-Star Thanksgiving Recipes” (7 p.m., Food).

• Scheduled on “48 Hours Mystery” (CBS), death row diaries (8 p.m), a con woman tells all (9 p.m.).

• Joseph Gordon-Levitt hosts “Saturday Night Live” (10:30 p.m., NBC), featuring musical guest Dave Matthews Band. This is their first appearance on “SNL” in nearly a decade.

Sunday’s highlights

• A stolen taxi puts one team at a disadvantage on “The Amazing Race” (7 p.m., CBS).

• Bart meets a grown-up version of himself (Jonah Hill) on “The Simpsons” (7 p.m., Fox).

• Despite his scheming, Larry misses a chance to be with Cheryl on the season finale of “Curb Your Enthusiasm” (8 p.m., HBO).

• Dexter plumbs the psyche of the Trinity killer on “Dexter” (8 p.m., Showtime).