It’s Labor Day, but not on television. Almost every major holiday, religious and secular, from Christmas to Veterans Day to Halloween, receives some television observation. Except Labor Day. You’d think maybe the History Channel would air some documentary about famous strikes, the murderous exploitation of coalminers, or the rise, corruption and decline of the union movement in America. Nope. Instead we get “Frat Boys” (8 p.m., History), a 90-minute history of college fraternities, and “Cleavage” (9:30 p.m., History), an hour and a half devoted to the enduring fascination with women’s bosoms — on the History Channel.

But it’s not just the History Channel. It’s every channel. If you want to observe Labor Day, go out and rent “Norma Rae,” “The Grapes of Wrath,” “On the Waterfront” or “Harlan County, USA.” You won’t see them tonight on television, where Labor Day doesn’t exist.

“Who Wants to Marry My Dad?” (9:10 p.m., NBC), the summer’s most cringe-worthy reality show, returns for a “reunion special.” Viewers get a chance to catch up (after two weeks) with Don and Christena, the woman Don’s four children chose as their new stepmother. Are they engaged? Do we care? We also get to hear from some of Don’s rejects as they explain what they’re doing now and how they feel about getting the heave-ho on national television.

Rejects from both installments of “For Love or Money” (8 p.m., NBC) return to share their feelings about Erin and Rob and their lost chances to cash that million-dollar check.

Tonight’s other highlights

• Comic Jamie Foxx impressed many in the 1999 football drama “Any Given Sunday” (7 p.m., ABC), starring Al Pacino and Dennis Quaid.
• An Oregon man thinks a family heirloom may have been a gift from Mark Twain on “History Detectives” (7 p.m., PBS).
• An inert piece of luggage speaks volumes on “Everybody Loves Raymond” (8 p.m., CBS).
• Homicide doesn’t stop for spring break on “CSI: Miami” (9 p.m., CBS).

Series notes

Sisterhood is powerful on “Yes, Dear” (7 p.m., CBS) … Drama precedes the big cotillion on “The O.C.” (7 p.m., Fox) … Jury duty on “The Parkers” (7 p.m., UPN) … Tara Lipinski guest stars on “7th Heaven” (7 p.m.).

Hot-tub schemes on “Paradise Hotel” (8 p.m., Fox) … Terror on the lake on “Everwood” (8 p.m., WB).

Late night

Al Franken appears on “Late Show with David Letterman” (10:35 p.m., CBS) … Jay Leno welcomes Sen. Hillary Clinton and Jay Mohr on “The Tonight Show” (10:35 p.m., NBC) … Reese Witherspoon appears on “Late Night with Conan O’Brien” (11:35 p.m., NBC).