If you’re going to nap, then you might as well nap correctly. Seems there’s a right and wrong way to nap, according to science. Apparently the ideal time of day to nap is between 1 p.m. and 4 p.m. But those are the best times to nap — not the duration. Dozing off for somewhere between 20 to 40 minutes after you’ve had lunch is the sweet spot. A nap of this duration at this time will keep you from being groggy and will (hopefully) give you the energy you need to power through the rest of your day.