MIAMI -- Jim Angleton's workday begins before dawn, so when his eyes get droopy by midafternoon, he just leans back at his desk and takes a nap.
"If I feel tired, my body is trying to tell me something, so I will excuse myself, shut the door, sometimes put headphones on and listen to music, and just put my head back and disconnect," said Mr. Angleton, 56, who owns a Miami Lakes financial services company.
Are you yawning yet?
Go for it: Today is Napping Day, an unofficial holiday created in 1999 by now-retired Boston University professor William Anthony and his wife, Camille, to help people adjust to daylight saving time.
After losing an hour of sleep Sunday by setting clocks forward, many in the workforce will drag through the day today; hence the need for a power nap.
How much sleep to get?
Newborns: 12 to 18 hours
Infants (3 to 11 months): 14 to 15 hours
Toddlers (1 to 3 years): 12 to 14 hours
Preschoolers: (3 to 5): 11 to 13 hours
School age: (5 to 10): 10 to 11 hours
Tweens and teens: (10 to 17): 8.5 to 9.25 hours
Adults: 7 to 9 hours
Source: National Sleep Foundation
"You get refreshed, you get re-energized and you get de-stressed," Mr. Angleton said. "I highly recommend it if you can get away with it. It's got to be good for the soul."
Everyone needs to sleep. Newborns require as much as 18 hours a day; adults, as a general rule, seven to nine hours, the National Sleep Foundation says.
"Sleep is essential for your overall wellbeing, quality of life, for your mood, for your growth, and also for the prevention of diseases, because the lack of sleep can trigger inflammatory response in your body and can make you more susceptible to infection," said Alexandre Abreu, co-director of the UHealth Sleep Center at the University of Miami Miller School of Medicine.
Naps can help, as long as they do not interfere with your nighttime sleep -- creating a vicious cycle, he said.
One-third of adults take regular naps, according to a poll by the Pew Research Center. And more men (38 percent) reported napping than women (31 percent)
The habit may start at an early age: preschoolers are accustomed to grabbing their blankets and going to sleep. It's also a cultural phenomenon. In many European and Latin American cultures, a siesta after lunch is still an important part of the daily schedule.
While naps do not necessarily make up for inadequate or poor-quality nighttime sleep, a short nap of 20 to 30 minutes can help improve mood, alertness and performance, according to the National Sleep Foundation.
Depending on your job, it may even be critical. A study at NASA on sleepy military pilots and astronauts found that a 40-minute nap improved performance by 34 percent and alertness by 100 percent.
And another study, in the October 2012 issue of Academic Medicine, found that among first-year internal medicine residents, a short midday nap improved alertness and cognitive functioning.
Yet, by and large, U.S. employers frown upon workers who try to nap on the job.
Naps are not right for everyone. Nap for too long, and you might be groggy instead of refreshed. Daytime sleeping could lead to insomnia. And if you already have trouble sleeping at night, a nap may only exacerbate the problem, said Dr. Abreu, the Miami sleep doctor.
In fact, the need for a nap may be a sign of a disorder, like disruptive sleep apnea or narcolepsy, he said.
"Take naps because it's cultural, as long as it doesn't interrupt nighttime sleep, or because you have poor sleep and need to perform at driving or work, so you're protecting yourself and others from your sleepiness," he advises.