V. The opposite of an all-nighter. An all-dayer occurs when a person has odd sleeping patterns. These habits result in a person going to bed anytime during the day. An all-dayer is the act of staying awake during the day instead of going to sleep. This act is usually performed in order to maintain a regular sleep schedule.
Mike: I'm going to sleep.
Jacob: Dude, WTF it's two in the afternoon.
Mike: I know. It's just that after that all-nighter I pulled for the calculus exam my sleep schedule has been off.
Jacob: Well, i've got tickets to the basketball game at five, and I thought you were going to go with me.
Mike: Oh snap, I totally forgot about that. I'll just pull an all-dayer so that I can go to the game.