During the day time, the Sun is out and most people are awake. They work, go to school, or complete daily errands and activities. Many people sleep for a short time in the early afternoon for a quick rest or because they are not able to sleep during the day. This is called a nap. A successful nap should run between 15-30 minutes, and longer naps taking 30-60 minutes will result in feeling dazed and less attentive.