Numerous accounts throughout history have been recorded of segmented sleep. Medical texts, court records, diaries, and even African and South American tribes, with a common reference to "first" and "second" sleep, have proven the existence of a “sleeping in shifts” practice. Today's society doesn't necessarily approve of this type of flexibility. It is generally thought a continuous 7 to 9-hour unbroken sleep is best for feeling refreshed. However, a split sleep schedule can provide some advantages – including the flexibility it allows with work and family time. Some people today have adopted this type of schedule as it provides two periods of increased activity, creativity, and alertness across the day. Learn more here.