Sometimes, confusion brings insight. When TBS sent me review material for “World’s Funniest Commercials” (89 p.m., TBS), my inner calendar did a double take. Don’t these advertising roundups usually air during the week between Christmas and New Year’s – the deadest week of the prime-time year, when there’s absolutely nothing on television?

But that got me thinking. The week before Labor Day is really a lot like the week after Christmas – but in reverse.

Both represent programming lulls, culminating in holiday-weekend marathon binges. And both seem dominated by football, except this week marks the beginning of the gridiron season and Christmas week, the end, or at least the beginning of the end.

Christmas can mean a house filled with new presents and unwrapped boxes, while the prospect of Labor Day portends wrapping up summer plans and packing up and preparing for school.

There’s a symmetry to these seasonal slow weeks, now book-ended by Kevin Nealon’s silly celebration of commercial breaks.

Nealon hosts “Commercials” from Paris, accompanied by actress Susan Yeagley, who just happens to be his wife. Look for silly spots from the United States, including a beer ad with almost every word bleeped out. Beer commercials from Russia to Australia to Romania put the emphasis on testosterone. And who can’t resist ads featuring dogs and babies, even infants driving SUVs? A British ad puts the old song “Ballroom Blitz” to good use, and a very strange commercial from Thailand features more apparitions than an episode of the “Ghost Whisperer.”

¢ Our summer of karaoke is not quite over yet. “Celebrity Rap Superstar” (9 p.m., MTV) challenges notables to spit out lyrics like rappers. On the show, eight contestants will pair off with a mentor and try to perform some of the best-known rap songs of all time in front of a studio audience and a panel of judges. Every week, the viewing audience will vote off a contestant until the best nouveau rapper emerges.

Tonight’s other highlights

¢ U.S. Open Tennis coverage (6 p.m., USA).

¢ Liz sees the sunny side of Cleveland on “30 Rock” (7:30 p.m., NBC).

¢ Michael listens to a more sensitive approach on “The Office” (8 p.m., NBC).

¢ A backyard murder sparks a scramble for evidence on “The First 48” (8 p.m., A&E).

¢ Contestants team up with fourth-graders to crack a secret code on “Who Wants to Be a Superhero” (8 p.m., Sci Fi).

¢ After a slight, Don decides to get even with Roger on “Mad Men” (9 p.m., AMC). Every time you think you understand Don Draper (Jon Hamm), his character gets darker and stranger.

¢ Paul Simon, Corinne Bailey Rae and Primal Scream appear on “Live From Abbey Road” (9 p.m., Sundance).

¢ David Letterman celebrates the 14th anniversary of “Late Show with David Letterman” (10:35 p.m., CBS) with guests Sen. Hillary Rodham Clinton, Willie Nelson and Kenny Chesney.

Cult choice

Thora Birch and Kelly Lynch star in the 2003 made-for-TV movie “Homeless to Harvard: The Liz Murray Story” (8:50 p.m., Lifetime Movie Network).

Late night

Stephen B. Hayes is scheduled on “The Daily Show with Jon Stewart” (10 p.m., Comedy Central) … Jay Leno hosts Jonah Hill, Michael Cera, Christopher Mintz-Plasse and Wilco on “The Tonight Show” (10:35 p.m., NBC) … George Lopez, Matt Dallas and Yung Joc appear on “Jimmy Kimmel Live” (11:05 p.m., ABC) … Kevin Bacon, Will Forte and Eisley chat on “Late Night with Conan O’Brien” (11:35 p.m., NBC) … Craig Ferguson hosts Pamela Anderson, Hans Klok, Avi Liberman and Nellie McKayon “The Late, Late Show” (11:37 p.m., CBS).