The calendar conspires to place St. Valentine’s Day on a Saturday night, making it the most romantic date night of the year — or the most forlorn, depending on your situation and attitude. For those who spend this pink night bathed in the blue glow of a television, the schedule offers many ways to celebrate or denigrate the occasion.

Viewers could strike a middle ground of sorts with the 1975 special “Be My Valentine, Charlie Brown” (7 p.m., ABC), an hourlong meditation on a depressed bald boy’s pining for a certain little red-haired girl.

Those seeking the sugar-rush of unalloyed romance could do worse than the original Hallmark presentation “Before You Say I Do” (8 p.m., today, Hallmark), starring David Sutcliffe of “Gilmore Girls” and Lauren Holly (“NCIS”), about a man who time travels to prevent his one true love from entering into a disastrous first marriage. Yikes.

The Oxygen Network recycles the 1993 heart-tugger “Sleepless in Seattle” (7 p.m., Oxygen) after spending the afternoon spooling movies with “love” in the title, including “Down With Love” (11:30 a.m.); “Can’t Buy Me Love” (2 p.m.) and “Love Actually” (4 p.m.).

Viewers with a different take can exult in the 12-hour marathon of “Cheaters” (5 p.m., Saturday, G4), a hidden-camera show in which suspicious spouses catch their straying partners in the act.

If love of country or history is your idea of hearts and flowers, there’s also “The Real Abraham Lincoln” (8 p.m., today, National Geographic). Filled with historical re-enactments, “Real” offers a survey biography of the Rail Splitter, a general history that may complement other Lincoln fare that has aired on PBS and History.

• Who says romance stirs only on Valentine’s Day? We’re all invited as “The World’s Heaviest Man Gets Married” (7 p.m., Sunday, TLC). Just two years ago, Manuel Uribe tipped the scales at 1,232 pounds, earning him his title. But behind every big man is a good woman. And over the past 24 months, he has shed more than 400 pounds and asked for her hand.

“Man” follows in the TLC tradition of romantic voyeurism as we watch the nervous groom prepare for the big day with an outfit requiring 13 feet of fabric for his shirt alone!

• “Masterpiece” (8 p.m., PBS, check local listings) offers a new adaptation of “Oliver Twist” by Charles Dickens, featuring an attractive cast of stylish urchins including newcomer William Miller in the title role. The provocative contemporary musical score and a performance by Timothy Spall (“Harry Potter”) as Fagin should not be missed.

Today’s highlights

• Joan Jett guest stars on “Law & Order: Criminal Intent” (7 p.m., NBC).

• A creepy predator works out of a gas station in the 2008 shocker “Splinter” (8 p.m., Sci Fi).

Sunday’s highlights

• “The Amazing Race” (8 p.m., CBS) begins its 14th season.

• Homer mulls might-have-beens on “The Simpsons” (7 p.m., Fox). Broadcast for the first time in high definition.

• Stephen Dorff and Val Kilmer star in the conclusion on the miniseries “XIII” (8 p.m., NBC).

• Tommy’s business plans shock Holly on “Brothers & Sisters” (9 p.m., ABC).

• A date with an Australian raises eyebrows on “Flight of the Conchords” (9 p.m., HBO).