Dayworld's a Philip José Farmer trilogy set in a dystopian future in which people live only a day a week. The other days they're stoned, a suspended animation. It focuses on Jeff Caird, a daybreaker: someone who lives more than a day a week. As the series progresses, he seems to suffer Dissociative Identity Disorder. The three parts are Dayworld ('85), Dayworld Rebel ('87), Dayworld Breakup ('90).
Caird's a citizen of Tuesday-World New Era 1330. The book starts on D5-W1 (Day-5, Week-1) in the 2nd Month of NE1330. (Each day of the week is the same day number, i.e. Sun-Sat will still be D5-W1). The book covers a week: Tuesday-World D5-W1 to Tuesday-World D6-W1. He's an 'organic' (police officer) by profession. Each day of the week organics have different outfits. Each day of the week has a different fashion trend, tv shows, news etc, most only knowing about each in their own day. He's also an immer, a group acting beneath governmental radar. Their goal's to subtly improve government. There are immers in almost every social sector in each day of the week. He's special in that he's a daybreaker as sanctioned by the immers, used to pass messages from day to day. As a daybreaker, he's mentally created a different identity for himself for each day of the week, different jobs, friends & wives included.