Most people try to get around eight hours of unbroken sleep each night. But that wasn’t always the preferred sleep pattern. In pre-industrial Europe, as well as in many other parts of the world, it was common for people to sleep in two segments, waking up for an hour or two in between, around midnight. These sleep shifts were known as “first sleep” and “second sleep,” and were referenced frequently in literary works and diaries from the period. Without electric lights, people would go to sleep fairly early, a couple hours after sundown. After waking up, during a period of time sometimes referred to as “the watching,” people would do indoor activities such as praying, reading, sewing, tending to the fire, or possibly socializing with neighbors. Some doctors even recommended this period of wakefulness as being the ideal time to conceive a child. Afterwards, people would go back to sleep for another few hours, waking up around dawn.
Getting some shut-eye:
The practice of sleeping in two segments is known as “biphasic sleep.” Taking an afternoon nap or siesta is a less extreme version of this practice, as people naturally tend to feel tired after lunch.
Some people find that they are more productive on a split sleep schedule, with two periods of wakefulness, rather than one long period in which they gradually become more tired towards the end of the day.
There are references to segmented sleep in the works of Charles Dickens, Geoffrey Chaucer, and Miguel de Cervantes, and even in Homer’s Odyssey.