Christmas arrives for NBC’s Thursday night comedy block. “Community” (7 p.m.) offers a savage and overdue sendup of “Glee.”

When the campus choir is busted for copyright infringement, its bubbly sweater-vested director, Cory Radison (Taran Killam, “Saturday Night Live”), tries to enlist the study group members to take their place. “No way” gives way to a cappella acceptance as he bewitches them one by one with songs perfectly pitched to their particular eccentricities.

The best of the silly song sendups has to be “Baby Boomer Santa,” an anthem of one generation’s self-centered view of the universe that appeals to the doddering Pierce (Chevy Chase). This is a memorable “Community” Christmas episode that will surely appeal to fans of the series and may turn some disinterested viewers into regulars.

”The Office” (8 p.m.) has a history of better-than-average Christmas episodes, dating back to the original British series that starred Ricky Gervais. Tonight’s episode is not the best of the batch but is still worth watching, if only to see the receptionist, Erin (Ellie Kemper), drown her jealousy of Andy’s (Ed Helms) girlfriend in an unending round of cocktails. Most of them are poured by Dunder Mifflin’s CEO, Robert California (James Spader), who also finds himself in a funk over the dissolution of his marriage.

While Helms has done a good job of replacing Steve Carell’s Michael Scott as the pathetic, clueless boss with a heart of gold, Spader’s character is a rather odd duck who has emerged as an enigmatic creep. Spader has done a brilliant job conjuring up this character, but it’s more often about improvisational honesty than comedy. In short, somebody’s forgotten that this show is supposed to be funny.

On the other end of the spectrum, the holiday episode of “Parks and Recreation” (7:30 p.m.) tiptoes dangerously close to sentimentality, as Leslie copes with her banishment from the office and the suspension of her campaign.

If “The Office” and “Parks and Recreation” occasionally forget to amuse this week, the laugh track-driven “Whitney” (8:30 p.m., TV-14) is convinced of its own hilarity. In what I sincerely hope is its first and final Christmas outing, Whitney hatches a devious scheme to spend the holiday without seeing her parents, played by Jane Kaczmarek and Peter Gallagher, who are far better than the dialogue they have to deliver.

Tonight’s other highlights

• The results are read on “The X Factor” (7 p.m., Fox).

• “Wipeout” (7 p.m., ABC) hosts its Christmas special.

• “The First 48” (8 p.m., A&E) returns with new episodes.

• Carter needs help on “Person of Interest” (8 p.m., CBS).

• A storm chaser gets way too close on “Bones” (8 p.m., Fox).

• Michael turns to Pearce on “Burn Notice” (8 p.m., USA).

• An investigation into the supposed death of an ex-NFL great on “The Mentalist” (9 p.m., CBS).

• A grisly discovery at a high school on “Grimm” (9 p.m., NBC).

• A high school reunion inspires memories on “It’s Always Sunny in Philadelphia” (9 p.m., FX).