Of the twenty-four equal hours into which they divide the day and the night, the Utopians devote only six to work. They work three hours before noon, when they go to lunch. After lunch, they rest for two hours, then go to work for another three hours. Then they have supper, and about eight o'clock (counting the first hour after noon as one) they go to bed, and sleep eight hours.
I read it as a teenager, at which stage I spent roughly 16 hours a day resting.