In terms of a specific sleep time, sleep expert Shawn Stevenson told Yahoo! that the optimal sleep schedule would be from 10 p.m. to 6 a.m. because of our body’s natural circadian rhythm and the fact that it mimics the sun’s rising and falling. Dr. Matt Walker, head of the Sleep and Neuroimaging Lab at the University of California, Berkeley, agrees, telling Time.com, “When it comes to bedtime, there’s a window of a several hours—roughly between 8 PM and 12 AM—during which your brain and body have the opportunity to get all the non-REM and REM shuteye they need to function optimally.”
Your own unique “perfect” bedtime within that window depends on genetics—some people are more naturally pre-disposed to be night owls, while others prefer to sleep earlier and wake up early. So, if you don’t tend to get sleepy until 11 p.m., don’t force yourself to go to bed at 9 in the hopes you’ll wake up feeling more refreshed. Most likely, this will backfire and you’ll toss and turn and wake up feeling groggier than if you had just gone to bed when you naturally started feeling sleepy.’
The Sleep Trick
If you’re trying to pinpoint the exact time, the easiest way is to go backwards. Figure out what time you need to wake up in the morning and subtract seven to eight hours, adding about fifteen minutes for your body to fall asleep. Do this for about 10 days and Michael Breus, PhD, a board-certified sleep specialist, tells Yahoo! that you should start naturally waking up a few minutes before your alarm sounds.