According to Newsarama, one of Dark Horse's final-produced 'Star Wars' tales will be a four-part miniseries entitled 'Darth Maul: Son of Dathomir,' arriving this May and drawing on actual screenplays for what was to be the 'Clone Wars' finale.
These are called rapid eye movement (REM) sleep, and non-rapid eye movement (Non-REM) sleep. In adults, non-REM sleep occupies around 80 percent of the night, and REM sleep 20 percent. However, REM sleep does not occur in one large block. Actually, we go into REM sleep in cycles of around 90 minutes. That is, REM sleep occurs around once every 90 minutes.
If you are younger, you need more sleep, with babies needing to sleep most of the day and night, and young adults needing about 8 hours sleep on average. The brain continues to develop well into our 20es. Four hours is the minimum amount of time it takes to go through at least one REM cycle and one deep sleep cycle.