Valentine’s Day approaches, and with it, obligatory holiday episodes.

As if the pathologically frisky folks on “Grey’s Anatomy” (8 p.m., ABC) needed any excuse, Cupid’s silhouette haunts Meredith and Derek. Forced romance does little for Liz Lemon’s love life on “30 Rock” (7 p.m., NBC). In case you’ve missed it, “Up All Night” (8:30 p.m., NBC) is dedicated to the dubious proposition that exhausted working parents of a newborn baby want to do anything but sleep. Stir Valentine’s Day into that contrived mix and you’ve got tonight’s episode.

The gang on the sorcery-themed “The Secret Circle” (8 p.m., CW) gather for an “anti-Valentine’s Day” slumber party. Surely nothing good can come of that.

Even business networks get into the cupid routine. “Love at First Byte” (8 p.m., CNBC) examines the growing matchmaking industry. We meet folks from giant corporations like Match.com and watch singles as they date successfully and not so happily after being set up by the billion-dollar dating industry.

Some companies use detailed surveys and complex algorithms. Some experts contend that the algorithms can tell when the daters are lying on their detailed surveys.

Others emphasize niche interests. We discover that one of the fastest-growing segments of cyber-savvy singles is the over-55 crowd. We are introduced to two folks who meet on a site just for motorcyclists and another couple who discover that their shared love of horses does not extend to each other.

The notion of computer dating is not exactly new. “Byte” unearths footage from the mid-1960s about two college students brought together by punch cards and an IBM mainframe. And we see them as they look today, still married after all these years.

Tonight’s other highlights

• The Hollywood round continues on “American Idol” (7 p.m., Fox).

• The teen brother of a murder victim becomes a “Person of Interest” (8 p.m., CBS).

• Pam’s maternity leave ends on “The Office” (8 p.m., NBC).

• A magician’s disappearing act works too well on “The Finder” (8 p.m., Fox).

• Jane defends an accused woman on “The Mentalist” (9 p.m., CBS).

• Sam finds his sister in the slammer on “Private Practice” (9 p.m., ABC).