A night owl , evening person or simply owl , is a person who tends to stay up until late at night, or the early hours of the morning. Night owls who are involuntarily unable to fall asleep for several hours after a normal time may have delayed sleep phase disorder. The opposite of a night owl is an early bird — a lark as opposed to an owl — which is someone who tends to begin sleeping at a time that is considered early and also wakes early. Researchers traditionally use the terms morningness and eveningness  for the two chronotypes or diurnality and nocturnality in animal behavior. In several countries, especially in Scandinavia , early birds are called A-people and night owls are called B-people.
Quiz: Are You an Early Bird or a Night Owl?
Night owl (person) - Wikipedia
Opposing body clocks can wreak havoc on a relationship if you don't take the time to understand why one of you just can't bounce out of bed in the morning, and the other effortless rises before the sun. Sleep researchers are becoming increasingly interested in chronotypes — that is, the body's natural body clock — and the way they influence everything in our lives from our work performance to our relationship satisfaction. Being romantically involved with someone whose body clock doesn't sync with yours can come with obvious challenges — one of you might love the idea of a smashed avo breakfast date, while the other is planning a late-night movie session. But by learning more about body clocks and understanding the legitimate biological differences that exist between morning and night-inclined people, sleep researcher Dr Elise Facer-Childs tells Coach our relationships could really benefit. Unfortunately, society tends to have a bias against night owls, labelling them lazy for having a sleep-in — even if they achieve the same amount in the day, just at a later hour.
Night owl (person)
You struggle into work in the dark hours before 10 a. So you push play, trade a bit of sleep for more Netflix time and continue the cycle that keeps you tired all the time. The trouble with being a night owl is that your sleep gets clipped in the morning hours, where most of the precious REM or dream sleep occurs. Instead of sleeping seven or eight hours per night, most night owls get forced to sleep five or six — with a hard start time in the morning. If you have the freedom to wake up when you like, then things are different, but if that extra Netflix episode is forcing you to cut your sleep short, then you should try to do something about it.
Last night I stayed up writing until am, then watched an episode of The West Wing to unwind before actually falling asleep at 3am. This not entirely unusual for me. I live on the west coast. That interaction, one could say, is the perfect symmetry of a friendship between a night owl and a morning person. The fact is, society tends to look down on those who stay up.