An all-nighter was a study or work session which lasted, as its name suggested, an entire night.
In 2267, Carolyn Palamas stayed up all night to work on her report on Pollux V, prompting Montgomery Scott to offer her some coffee to wake her up. (TOS: "Who Mourns for Adonais?")
In 2366, Wesley Crusher pulled an all-nighter in order to work on his nanite project, during which he fell asleep and, upon waking, noticed that the container was open. (TNG: "Evolution")
Kathryn Janeway was famous at Starfleet Academy for her all-nighters. (VOY: "Darkling", "Good Shepherd")
In 2373, after asking a sleepy Kes whether she had done an all-nighter, Janeway defined it as "The fine art of putting off an important task until the last minute, then rushing through it." (VOY: "Darkling")
In 2376, while comparing her study habits with Tal Celes, Janeway shared her propensity for all-nighters. Celes then admitted she had done the same, every night, claiming it was the only way she passed her courses. (VOY: "Good Shepherd")