Astronauts need to be very wise in their use of time when in space. Crews on earth plan the daily tasks that every astronaut must complete every day, in five-minute intervals. Times for meals, exercise, sleep and free-time are all planned. This article explains some of the things that must be considered when scheduling an astronaut's day:
In his book "Endurance", astronaut Scott Kelly talks about the challenges of returning to daily life on earth, after living about the ISS for a year, because he was suddenly responsible for organizing his own time.