Night owl (person)
A night owl or evening person is a person who tends to stay up until late at night.
The opposite of a night owl is an early bird, a lark as opposed to owl, someone who tends to begin sleeping at a time that is considered early and also wakes early. In several countries, early birds are called "A-people" and night owls are called "B-people." Researchers traditionally use the terms "morningness" and "eveningness" for the two chronotypes.
Origins and characteristics 
The term is derived from the primarily nocturnal habits of the owl. Usually, people who are night owls stay awake past midnight and extreme night owls may stay awake until just before or after dawn. Night owls tend to feel most energetic just before they go to sleep at night. Some night owls have a preference or habit for staying up late, or stay up to work the night shift. Night owls who work the day shift often have a problem with being on time for work.
Researchers have found that "differences in a fundamental property of the circadian timing system, its intrinsic period, will determine whether someone is an early bird, who awakens before dawn, or a night owl, who tends to stay up late at night but sleeps in late." Some night owls who have great difficulty adopting normal sleeping and waking times may have delayed sleep phase disorder. It has been suggested that "circadian rhythm can change over the course of a lifetime so that a onetime early riser becomes a night owl later on (or vice versa)." Light therapy may be helpful "if you are the night owl type...[to] shift your sleep rhythm so that you can fall asleep sooner in the evening and wake up earlier in the morning."
Often in a work context, "night people are viewed as lazy, undisciplined, unpunctual or as having an attitude problem...Night people have been speaking out against this bias, though, until recently, mainly in a humorous vein." However, in January 2007, night owls in Denmark began a serious push for change. They formed the "B-Society", arguing that the early bird model was inappropriate for a post-agricultural world and lobbying for "a more flexible workplace".
Others would celebrate the status of night-owl. "As one of the night people, I realized I was among the select....We have the world to ourselves." "Blessed are the owls, for they shall inherit the mystery and magic of the night."
Discussions and studies about the prevalence of morning, evening, and indifferent or intermediate chronotypes use different criteria and come to different results. Some ask what time people do go to sleep and wake up—others ask what time people would prefer to. A survey of over 400 adults showed approximately 15% morning people, 25% evening people, and 60% intermediates.
Famous and literary exemplars 
A list of famous night owls includes:
In Jayne Ann Krentz's Truth or Dare, "Arcadia and Harry were both creatures of the night. They managed to appear oddly stylish at one-thirty in the morning." When Arcadia's life is threatened, Harry suggests they immediately contact their friendly neighbourhood P.I.,[clarification needed] only for Arcadia to object: '"It's one-thirty a.m. He and Zoe will be sound asleep." "Not our fault those two keep weird hours."'
See also 
- James, Kyle (1 March 2007). "Late Sleepers in Denmark Rally for Societal Change". Deutsche Welle. Retrieved 2009-11-01.
- Morris, Chris (14 June 2007). "Late risers unite in Denmark". BBC News Channel. Retrieved 2009-11-01.
- Horne JA, Östberg O (1976). "A self-assessment questionnaire to determine morningness-eveningness in human circadian rhythms". Int J Chronobiol 4 (2): 97–110. PMID 1027738.
- Charles A. Czeisler, quoted in Philip Lee Williams, On the Morning (2006) p. 41
- Jeff Belanger/Kirsten Dalley, The Nightmare Encyclopedia (2005) p. 83
- Laura H. Smith/Charles H. Elliott, Seasonal Affective Disorder for Dummies (2007) p. 73
- Gayle Greene, Insomniac (2008) p. 345
- Greene, p. 345
- Anon, in Hilary Rubinstein, The Complete Insomniac (London 1974) p. 18
- Rubinstein, p. 19
- Schur, Carolyn (1994). "excerpt". Birds of a Different Feather. Saskatoon, Canada: Schur Goode Associates. ISBN 0-9698190-0-5. Retrieved 2009-07-20.
- "Famous Night People"
- Robert G. Moeller "The Nazi State and German Society" (Bedford Books, 2010), 169-170.
- Quoted in Rubinstein p. 211
- Jayne Ann Krentz, Truth and Dare (Penguin 2004) p. 258
- Krentz, p. 252-3
Further reading 
Louise Miller, Careers for Night Owls and Other Insomniacs (2002)