World Library  
Flag as Inappropriate
Email this Article

Leap Day

Article Id: WHEBN0000433178
Reproduction Date:

Title: Leap Day  
Author: World Heritage Encyclopedia
Language: English
Subject: Peanuts, James Mitchell (actor), John Cullum, WDNC, Jason Litzau, Ann Marie Calhoun
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Leap Day

This article is about the calendar day. For the South Korean film, see February 29 (film).
"Leap Day" redirects here. For the "30 Rock" episode, see Leap Day (30 Rock). For the "Modern Family" episode, see Leap Day (Modern Family).
1
2 3 4 5 6 7 8
9 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28
Template:ThisDateInRecentYears/validate

February 29, also known as the leap day of the Gregorian calendar, is a date that occurs in most years that are divisible by 4, such as 2004, 2008, 2012, 2016 and 2020. Years that are divisible by 100, but not by 400, do not contain a leap day; thus 1900 did not contain a leap day while 2000 did. Years containing a leap day are called leap years. February 29 is the 60th day of the Gregorian calendar in such a year, with 306 days remaining until the end of the year. For the Chinese calendar, this day itself in February will only occur in years of the monkey, dragon and rat.

Leap years

Main article: Leap year

Although most modern calendar years have 365 days, a complete revolution around the sun (one Solar year) takes approximately 365 days and 6 hours. An extra 24 hours thus accumulates every four years, requiring that an extra calendar day be added to align the calendar with the sun's apparent position. Without the added day, the seasons would move back in the calendar, leading to confusion about when to undertake activities dependent on weather, ecology, or hours of daylight.

A solar year, however, is slightly shorter than 365 days and 6 hours (365.25 days). More precisely, as derived from the Alfonsine tables, the Earth completes its orbit around the Sun in 365 days, 5 hours, 49 minutes, and 16 seconds (365.2425 days). Adding a calendar day every four years would thus add an extra 43 minutes and 12 seconds to the calendar, or 3 days every 400 years. To compensate for this, three leap days must be omitted every 400 years. The Gregorian calendar reform implemented this adjustment by making an exception to the general rule that there is a leap year every four years. Instead, a year divisible by 100 would not be a leap year unless that year was also exactly divisible by 400. This means that the years 1600 and 2000 were leap years, as will be 2400 and 2800, but the years 1700, 1800, and 1900 were not, nor will 2100, 2200, and 2300.

The Gregorian calendar repeats itself every 400 years, which is exactly 20,871 weeks including 97 leap days. Over this period, February 29 falls on Sunday, Tuesday, and Thursday 13 times each; 14 times each on Friday and Saturday; and 15 times each on Monday and Wednesday. The order of the leap days are: Thursday, Tuesday, Sunday, Friday, Wednesday, Monday and Saturday.

The concepts of the leap year and leap day are distinct from the leap second, which results from changes in the Earth's rotational speed.


The leap day was introduced as part of the Julian reform. The day following the Terminalia (February 23) was doubled, forming the "bis sextum"—literally 'double sixth', since February 24 was 'the sixth day before the Kalends of March' using Roman inclusive counting (March 1 was the 'first day'). Although exceptions exist, the first day of the bis sextum (February 24) was usually regarded as the intercalated or "bissextile" day since the third century.[1] February 29 came to be regarded as the leap day when the Roman system of numbering days was replaced by sequential numbering in the late Middle Ages.

Events

Births

A person who is born on February 29 may be called a "leapling" or a "leap year baby". In non-leap years, some leaplings celebrate their birthday on either February 28 or March 1, while others only observe birthdays on the authentic intercalary dates, such as February 29 leap days.

In the United Kingdom and Hong Kong, a person born on February 29 legally attains the age of 18 on March 1 in the relevant year.[2][3]

In New Zealand, a person born on February 29, is deemed to have their birthday on February 28 in non-leap years, for the purposes of Driver Licensing under §2(2) of the Land Transport (Driver Licensing) Rule 1999.[4] The net result is that for drivers aged 75, or over 80, their driver licence expires at the end of the last day of February, even though their birthday would otherwise fall on the first day in March in non-leap years. (Otherwise, New Zealand legislation is silent on when a person born on 29 February has their birthday, although case law[5] would suggest that age is computed based on the number of years elapsed, from the day after the date of birth, and that the person's birth day then occurs on the last day of the year period. This differs from English common law where a birthday is considered to be the start of the next year, the preceding year ending at midnight on the day preceding the birthday. While a person attains the same age on the same day, it also means that, in New Zealand, if something must be done by the time a person attains a certain age, that thing can be done on the birthday that they attain that age and still be lawful.)

In Taiwan (Republic of China), the legal birthday of a leapling is February 28 in common years:

"If a period fixed by weeks, months, and years does not commence from the beginning of a week, month, or year, it ends with the ending of the day which proceeds the day of the last week, month, or year which corresponds to that on which it began to commence. But if there is no corresponding day in the last month, the period ends with the ending of the last day of the last month.[6]"

Thus, in England and Wales or in Hong Kong, a person born on February 29, will have legally reached 18 years old on March 1. If he or she was born in Taiwan he or she legally becomes 18 on February 28, a day earlier. In the United States, according to John Reitz, a professor of law at the University of Iowa, there is no "... statute or general rule that has anything to do with leap day."[7] Reitz speculates that "March 1 would likely be considered the legal birthday in non-leap years of someone born on leap day,"[7] using the same reasoning as described for the United Kingdom and Hong Kong.

There are many instances in children's literature where a person's claim to be only a quarter of their actual age turns out to be based on counting their leap-year birthdays. A similar device is used in the plot of Gilbert and Sullivan's 1879 comic opera The Pirates of Penzance: As a child, Frederic was apprenticed to a band of pirates until his 21st birthday. Now, having passed his 21st year, he leaves the pirate band and falls in love. However, since he was born on February 29, that day will not arrive until he is in his eighties. As such, he must leave his fiancée and return to the pirates. It may be worked out from the opera's dialogue[8] that Frederic's birthday is February 29, 1852 thus making the opera set in 1873. (This assumes that Frederic is aware that 1900 will not be a leap year. If not, the dates would be later by four years.) This plot point was also used in a Sherlock Holmes story based on the Basil Rathbone era, where a friend of Dr. Watson's is a baronet who is due to receive his inheritance on the New Year's Day of the year where his twenty-first birthday will be celebrated, only for the law to deprive him of the money as he was born on February 29; with the 84-year-old Baronet distraught at the news that 1900 is not a leap year, Holmes helps the Baronet fake his death long enough for his grandson- who is the appropriate age to receive the inheritance- to establish his claim and receive the money himself.

A Utah woman has given birth on February 29 three times (2004, 2008, 2012). She shares the record for Leap Day births with a Norwegian woman (1960, 1964, 1968).[9]

Other notable persons born on February 29:

Deaths

Holidays and observances

Folk traditions

There is a popular tradition in some countries that a woman may propose marriage to a man on February 29. If the man refuses, he then is obligated to give the woman money or buy her a dress. In upper-class societies in Europe, if the man refuses marriage, he then must purchase 12 pairs of gloves for the woman, suggesting that the gloves are to hide the woman's embarrassment of not having an engagement ring. In Ireland, the tradition is supposed to originate from a deal that Saint Bridget struck with Saint Patrick.[10][11]

In Greece it is considered unlucky to marry on Leap Day.[12]

Rare Leap Day milestones

The only notable person known to have both been born and died on February 29 was Sir James Wilson (1812–1880), Premier of Tasmania.[13]

In 2012, a Utah woman gave birth for the third time on a consecutive Leap Day, tying a record set in the 1960s. The only other known case of triple Leap Day babies is from a family in Norway, which recorded Feb. 29 births in 1960, 1964 and 1968, according to the Guinness World Records press office.[14]

References

External links

  • BBC: On This Day
  • : On This Day
  • On This Day in Canada

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 



Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.