Justified 10 p.m., FX
Are you not watching this show, which returns for season four tonight? It’s among the best TV dramas, not least of all thanks to Timothy Olyphant’s cool performance as the Elmore Leonard-created US Marshal Raylan Givens. The show isn’t just about crime-solving; it’s about backwoods characters who are funny, desperate, and macabre. This season, a bunch of new characters show up as Raylan investigates a 30-year-old case. Among them: Patton Oswalt as Raylan’s very own Barney Fife. Pictured: Olyphant (left) and Oswalt.
Happy Endings 9 p.m., Channel 5
I loved this show, and then I hated it, and then we made up, and now I love it again but understand why some people hate it. It’s about a group of friends who are so thoroughly, unhealthily, sweetly enmeshed that they practically have their own “Nell”-style language. They talk too fast, all the while dropping countless allusions to pop culture and to their own histories. It’s very different from “30 Rock,” but both shows are so crammed with jokes you can — and sometimes need to — watch them twice to get everything. Tonight, Max has an identity crisis. Pictured: Elisha Cuthbert and Casey Wilson.
Diggers 10 and 10:30 p.m., National Geographic
Grazing in the grass is a gas.
Betty White’s Off Their Rockers 8 and 8:30 p.m., Channel 7
Psy guests. Oppan denture style.
Ben and Kate 8:30 p.m. Channel 25
BJ has a mother.Matthew Gilbert can be reached at firstname.lastname@example.org. Follow him on Twitter @MatthewGilbert.