The Exact Time You Should Go To Bed

By Melissa Walker at Yahoo Health

While everyone's sleep needs are a little bit different, there is a simple trick to help you figure out your perfect bedtime. 

Blackout blinds, white-noise machines, prescription medication - we'll try a lot of tricks to get a full night's sleep. Studies show that sleep is critical for our moods, our minds, and our overall health, and we just plain feel better after a good rest. But how do we know if we've gotten that ever-elusive "right amount" of sleep? It turns out that there's a science to doing it well.

"There is absolutely a right time to go to bed," says Michael Breus, PhD, a board-certified sleep specialist and author ofGood Night: The Sleep Doctor's 4-Week Program to Better Sleep and Better Health. That right time is unique to each individual Breus tells Yahoo Health, but there's a formula that will help you figure out your own magic hour.

"The average sleep cycle is 90 minutes long, and the average human has five of those sleep cycles per night," explains Breus. That means we all need around 7.5 hours of shuteye - he says the 8-hour advice touted everywhere is a myth. (While 7.5 is a good center gauge for most people, everyone's sleep needs are slightly different, with some people needing more or less sleep than others.) 

So how to get your 7.5 in? "Work backward from your wake-up time," says Breus. "That's socially determined by when you have to get up to get to work, get the kids ready, all those external factors." So if you have to get up by 6:30 a.m., count back 7.5 hours and recognize that your bedtime should be 11 p.m.

"Follow that bedtime for 10 days in a row," says Breus, "and you'll begin, quite naturally, to wake up a few minutes before your alarm clock sounds." It's key, he stresses, to be consistent - that's how the human circadian system functions best. "Sleeping in on the weekends causes your system to shift and makes you want to go to bed later and wake up later," he says. That's one reason why Monday mornings can feel so difficult - Breus calls that bedraggled feeling "social jet lag."

But what about people who say they can't fall asleep at 11 p.m., for example? "It's all about the wake-up time," insists Breus. "I don't care if you can't fall asleep at 11 p.m. initially. If you are consistent about getting up at 6:30 a.m. every morning, your body will adjust."

Here are three easy things you can do to improve your zzs: 

1. Set a nighttime alarm. If you have to go to bed at 11 p.m., set your alarm for 10:30 p.m. and it'll remind you to get ready for bed so you'll meet your nocturnal deadline. If you're consistent about waking time, a morning alarm will become unnecessary, says Breus.

2. If you work with a computer all day, try f.lux. It's a program that makes the brightness of your screen adapt to the time - warm at night, and brighter, like sun, during the day. It's especially great for late-night work, because if you check your computer at midnight, you don't want to be looking at a bright screen. (You can use the app for your phone too.)

3. As soon as possible after you wake up, get into the sunshine. Whether that means reading the newspaper out on the patio or standing by a window as you sip your coffee for 15 minutes, soaking up a bit of sunshine will reset your circadian clock and help your body's natural sleeping-waking rhythm.