There's nothing like a power nap to restore energy and improve productivity. Now you can get the "ultimate" power nap by timing it precisely for when your body and mind may most need it, using this Take a Nap Nap Wheel.
According to Dr. Sara Mednick, a sleep researcher and author of the Take a Nap! book, the ideal napping time is the point in the day when REM and slow-wave sleep (a.k.a. deep sleep) cross. In the moveable nap wheel, drag the wake up time dial to when you woke up and find where the blue and yellow circles intersect to see what time to hit the sack. In this example, if you wake at 7am aim for a 2pm nap.
Previously mentioned cheat sheet for power naps also gave an approximation for the best time to nap, but based on if you were a night owl or a lark. This nap wheel is more precise—though, of course, you don't have to nap at exactly that time. Getting a nap in any time around that sleepy period is like rebooting your brain.