Ready for a "Harry Potter Wizarding Weekend"?

All eight films adapted from the novels will air on both USA and Syfy over the next three days and nights, beginning with the 2001 adventure "Harry Potter and the Sorcerer's Stone" (8 p.m., TV-PG).

The action will conclude on Sunday with "Harry Potter and the Deathly Hallows" Parts 1 and 2 (5:15 p.m.).

Among the most popular young adult novels ever, the "Harry Potter" canon has inspired one of this century's most lucrative film franchises.

Until recently, these films have been exclusively available on HBO. For years, they were a staple of ABC and Disney programming.

Clearly, J.K. Rowling's books are held in great affection by generations of readers.

That adoration ran into interesting corporate and legal complications last month when Warner Bros. sought to crack down on unsanctioned Harry Potter role-playing festivals and a Quidditch tournament in Philadelphia.

In a written statement, the studio said it appreciated the fans' enthusiasm but worried that their activities had become too "commercial."

It's a curious and telling turn of events. Many of today's most enduring sci-fi and comic book franchises, most notably "Star Trek," were long kept alive by unauthorized gatherings and conventions that made Comic-Con a massive merchandising industry encompassing many properties and genres.

After NBC canceled "Star Trek" in 1969, Paramount didn't have a clue about its popularity until unofficial fan organizations and gatherings became too hard to ignore.

A 1979 movie officially revived "Star Trek," and it's been around ever since.

The "Harry Potter" franchise was hugely popular from the beginning, so perhaps Warner Bros. believes it doesn't need to indulge fans engaging in unlicensed frolics.

But in doing so, it risks coming off like Voldemort if it alienates the most passionate enthusiasts.

- Having served up seasons of "Undercover Boss," CBS launches "Whistleblower" (8 p.m.), tales of everyday employees who risked their livelihoods and even their safety to expose dangerous and illegal practices by their employers.

Former judge and police officer Alex Ferrer hosts. The first episode profiles an employee who took on the pharmaceutical giant Bristol-Myers Squibb.

- Netflix begins streaming the new stand-up special "Jim Jefferies: This Is Me Now" (TV-MA) and the 2013 concert "Kevin Hart: Let Me Explain."

- Hulu begins streaming the Canadian sitcom "Letterkenny," set in a quirky small town.

- Shudder, the subscription streaming service specializing in horror, thriller and supernatural movies, invites viewers to "The Last Drive-In With Joe Bob Briggs," a 24-hour marathon of 13 cult classic movies curated by the Texas-born movie critic and unabashed celebrator of exploitation movies.

His picks include "Tourist Trap," "Sleepaway Camp" and "Basket Case."

Tonight's other highlights

- "Vice" (7:30 p.m., HBO, TV-14) looks at a generation affected by opioid abuse and rising Hindu nationalism in India.

- The surgery ward is overwhelmed on "The Resident" (8 p.m., Fox, r, TV-PG).

- A new threat puts family members in peril on "Quantico" (8 p.m., ABC, TV-14).

- Crew members undertake a dangerous mission to retrieve the Krill bible on "The Orville" (8 p.m., Fox, r, TV-PG).

- John Quinones hosts "What Would You Do?" (9 p.m., ABC, TV-14).

- Danny mulls a career upgrade on "Blue Bloods" (10 p.m., CBS, r, TV-14).

- "Dateline" (10 p.m., NBC) recalls the Jonestown cult and the mass suicide of its followers in 1978.

Series notes

Minneapolis hosts "American Ninja Warrior" (8 p.m., NBC, r, TV-PG) ... On two episodes of "Masters of Illusion" (CW, TV-14), Titou (8 p.m.), Ed Alonzo (8:30 p.m., r).

Diamond thieves and body snatchers on "Hawaii Five-0" (9 p.m., CBS, r, TV-14) ... Illusionists audition on "Penn & Teller: Fool Us" (9 p.m., CW, r, TV-PG) ... "20/20" (10 p.m., ABC).

Late night

Jimmy Fallon welcomes Jared Leto and Alessia Cara on "The Tonight Show" (11:35 p.m., NBC, r) ... "Jimmy Kimmel Live" (11:35 p.m., ABC) is a repeat.

Paul Rudd and Florence & the Machine visit "Late Night With Seth Meyers" (12:35 a.m., NBC, r) ... Tracy Morgan, Ike Barinholtz and Weezer appear on "The Late Late Show With James Corden" (12:35 a.m., CBS, r).