When did the “real” 1960s begin? Many cultural historians and pop-culture buffs associate the tumultuous era with the longhaired youth, antiwar protesters, riots and rebellion of the decade’s concluding years. They argue that the “real” ’60s only began with Vietnam, or the Beatles, or the spirit of disillusionment evoked by the Kennedy assassination.

But the “Independent Lens” (9 p.m., KTWU; 10 p.m., KCPT) documentary “February One: The Story of the Greensboro Four” makes a solid case that the spirit of the decade was born on the first day of the second month of 1960. It was on that day that four black college freshman at North Carolina A&T State University began a peaceful sit-in at the lunch counter at their local Woolworth’s store.

Their protest was reported by the local media and then gained national attention. Within days, hundreds of black students and sympathetic whites engaged in similar demonstrations in dozens of cities.

• “Keeping the Faith: Becoming a Priest in Today’s Catholic Church” (9 p.m., Discovery Times) follows 42 men in an Ohio seminary. They speak frankly about their now unusual vocation and the changes and controversies facing the church.

Tonight’s other highlights

• More auditions on “American Idol” (7 p.m., Fox).
• Richard and Emily’s romantic collision on “Gilmore Girls” (7 p.m., WB).
• A patient refuses treatment on “House” (8 p.m., Fox). Brandy (“Moesha”) guest stars.
• After a teen star is raped, the son of a movie critic becomes the prime suspect on “Law & Order: Special Victims Unit” (9 p.m., NBC).

Late night

Al Franken, Amanda Bynes and Nanci Griffith appear on “Late Show with David Letterman” (10:35 p.m., CBS) … Jay Leno hosts Leonardo DiCaprio and Kenny Chesney on “The Tonight Show” (10:35 p.m., NBC) … Jeff Foxworthy, Matthew Fox and Chewbacca appear on “Jimmy Kimmel Live” (11:05 p.m., ABC).

Jeffrey Tambor and Maroon 5 chat on “Late Night with Conan O’Brien” (11:35 p.m., NBC) … Craig Ferguson hosts John Laroquette and Rickey Smiley on “The Late, Late Show” (11:37 p.m., CBS).