In America, everyone knows of the “full eight hours” of sleep they should be getting every night. Experts, doctors, even parents and teachers, insist on eight consecutive hours to be well-rested and prepared for the day ahead. This is monophasic sleeping.

Most people are monophasic sleepers, meaning that they sleep for one 6-8 hour period every 24 hours. It is thought that this custom was suited to the evolution of the 9-5 workday, when artisan, handmade works shifted to mass production, and the standard working hours only left the night time for sleeping.

While some people have easily fallen into routines to meet such requirements, others who struggle to fall asleep panic when they think of how their time for sleep is ticking down. 

Luckily, monophasic sleep is not your only option.

Biphasic sleeping, also known as diphasic, bifurcated, or bimodal sleep, refers to when there are two segments of sleep in a time span of 24 hours. It could be as simple as sleeping a little less overnight and taking a nap midday, but it can also look like two structured four-hour periods across the entire day. 

Some cultures already practice biphasic sleeping. The afternoon “siesta” in Hispanic countries and “mesimeri” in Greece fit the mold of biphasic sleeping, as it is normal for people to go home and take a nap, typically from 2pm-5pm. Restaurants and stores are closed during this time while the owners rest and the streets are empty.

However, a more extreme version of biphasic sleeping has become more popular in recent decades. Often, people split up their sleep into two four-hour sections. For example, your two sleeping periods could be from 2am to 6am and 1pm to 5pm. Most people who practice biphasic sleeping in this manner split up their consequential awake segments into work and relaxation. 

This is especially common among college students – many may even do it without realizing it. Having one awake period for classes and work and the other for relaxation, or what some practiced biphasic sleepers call “me hours,” can be beneficial in organizing one’s time.

Many biphasic sleepers feel as though their relaxation period allows them to accomplish much more than a typical schedule would allow, describing it as more “intentional and productive” than the free time they spend on a monophasic sleeping pattern.

So why does it work? Well, both science and history imply that biphasic sleeping was natural for humans and a very common practice until it began to fall out of favor in the 18th and 19th centuries with the growth of modern industry.

In the 1990s, Thomas Wehr conducted a study in which participants were in darkness for 14 hours a day for a month. What he found was that by the fourth week, all of the subjects naturally adapted to a sleeping pattern of sleeping for four hours, waking for one to two hours, and falling back asleep for another four.

Historical evidence of a biphasic sleeping pattern in humans is overwhelming. In 2001, Roger Ekrich published a paper with 16 years of research that supported the idea that humans slept in two separate segments, drawing from diary entries, medical books, literature, and court records.

In these documents, this type of sleeping pattern was referenced often and as common knowledge. People would smoke, write, pray, or even talk to neighbors. It was the same as what Wehr’s study found, with the first segment occurring just after dusk and having a waking period of about two hours before another segment of sleep.

One of these documents was an Old English ballad called “Old Robin of Portingale” found in the Percy Folio, a book of English poetry compiled in the 17th century by Thomas Percy.  It says, “At the wakening of your first sleepe You shall haue a hott drinke made, And at the wakening of your next sleepe Your sorrowes will haue a slake.”

The phrases “first sleep” and “second sleep” are common in works from these times, such as Don Quixote or Barnaby Rudge. 

While our society today is heavily structured and influenced around a consecutive eight hours of sleep during the night, it doesn’t mean you are limited forever. Trying biphasic sleeping when you have the time is definitely worth it. Before starting, consider your work schedule, whether it be school or a job, and think about what times of day would personally suit what you want to accomplish. Set your alarms and give yourself some leeway – you may just find yourself a biphasic sleeper.