A day, usually on a weekend or during a day off, when you have nothing to do and sit around lazily in your pajamas, not leaving the
house. Often involves eating
cereal for every meal and excessive
television/video games.
Speaker 1: "Hey, want to go see a movie?"
Speaker
2: "No
way man, I'm having a pajama day. Let's just sit around and watch
Seinfeld reruns."