This Perfect Day is an anti-utopian science-fiction novel by Ira Levin.

Warning: Wikipedia contains spoilers

The book follows the struggles of Li RM35M4419 (or Chip, as he likes to call himself) to free himself from this tightly programmed and controlled world, in which all the inhabitants are genetically engineered and drugged into a calm state of mind.

It is set in a seemingly perfect global society whose genesis remains vague ("Christ, Marx, Wood and Wei led us to this perfect day" is what schoolchildren learn to chant).

The world is ruled by a central computer called UniComp which has been programmed to keep every single human on the surface of the earth in check. People are continually drugged by means of regular injections so that they can never realize their potential as free agents. They are told where to live, what to eat and which job they will be trained for and work at. Everyone is assigned a counselor who acts somewhat like a mentor, confessor and parole agent; violations against 'brothers' and 'sisters' by themselves and others are expected to be reported at a monthly confession.

Everyone wears a bracelet with a tag for access points that act as a scanner which tells them where they are allowed to go and what they are allowed to do. At 62, people die; whether this is from one last dose of the monthly medication or perhaps a long accumulation of poisons, is unknown.

Even opposition against such a life by those few who happen to be resistant to the drug, or those who purposely change their behavior to avoid strong doses of some of the drugs in the monthly cocktail, and who consequently wake up to a day which for them turns out to be anything but perfect is dealt with by the programmers of UniComp. These long-lived men and women, in their underground hideaway, constitute the world government. Their ideology seems to be basically communist, but at the same time they choose their own members through a form of meritocracy. In part, people who choose, through evasion and modifying their own behavior, to leave the main Family are subtly re-directed to 'nature preserves' of imperfect life on islands. These, however, have been put in place by the programmers as a place to isolate trouble-making Family members.

See also: World government