Tina fey received a well-deserved Emmy nomination for her performance in this episode, only for her to lose out to Ugly Betty's America Ferrera. Ironically enough, she references that show in the teaser, when Liz tries to get out of Jack'office without being seen by Bianca (she's there to finalize the divorce), fails and quips: "This would have worked on Ugly Betty." The remaining 18 minutes, as always, live up to the first two effortlessly.
The context of the episode is Valentine's Day, usually a time of happiness. For the writing staff of TGS, it's anything but, since they are forced to remain in the office all night in order to meet a deadline. This causes problems for almost everyone, especially Pete, who forgot that it's also his wife's birthday, and Tracy, who traditionally spends that particular night engaging in some role-play with the missus. As the evening goes on, Liz receives flowers from an unknown suitor, and the guys decide to have some fun by telling Kenneth he should try to hit it off with Cerie.
This episode is notable for several things. Among others, it introduces Mrs. Jordan, who will have an important role early in the second season, and features a priceless Rachel Dratch playing a hooker. And of course, there are golden lines galore. The entire divorce scene is a lesson in comedy writing, narrowly beaten by Jack's previous conversation with Liz: "One minute you're making sweet love on a Concorde, the next you've got lawyers fighting over the box your dog defecates in." "You taught your dog to poop in a box?" "Bianca did. But damn it, I want that box!".
Oh, and Up All Night has what could be Frank's best line ever: when he says he's got special plans for Valentine's, Liz asks who with. Answer? "No one!".