February 29th, or bissextile day, is the 60th day of a leap year in the Gregorian calendar, with 306 days remaining. A year which has a February 29 is, by definition, a leap year. This date only occurs every four years, in years evenly divisible by 4, such as 1988, 1996, or 2008, with the exceptions in century years not divisible by 400, such as 1900.
Leap years come about mainly due to a technicality in the number of days in a year. Technically, a year consists of approximately 365 days and 6 hours. Therefore, every four years, an extra day is added to account for the extra twenty-four hours that have accumulated.
A century year, that is, a year which ends in two zeros (1800, 1900, 2000, etc.), is not a leap year unless it is also evenly divisible by 400. This means that the year 2000 was a leap year and 2400 and 2800 will also be, but 1800 and 1900 were not leap years, and the years 2100, 2200, and 2300 will not be leap years either. To correct a slight inaccuracy that remains in the Gregorian calendar, it has been proposed that years evenly divisible by 4000 should not be leap years, but this rule has not been officially adopted.
Because of this, a leap day is more likely to fall on a Monday than on a Sunday. If, for example, February 29 falls on a Sunday, you would expect it to fall on Sunday again after 28 years, but if there's a century year in these 28 years, the pattern can become disrupted. The Gregorian calendar repeats itself every 400 years, and 400 years have 97 leap days, which is not divisible by seven, so these days can never be distributed evenly. A leap day on a Sunday occurs 13 times in these 400 years, so approximately every 30.8 years, a Monday however occurs 15 times, which is roughly every 26.7 years. The concepts of the leap year and 'leap day' are distinct from the leap second, which is necessitated by changes in the Earth's rotational speed.
Those who are born on this day usually celebrate their birthdays on February 28 or March 1 during non-leap years. In the comic musical The Pirates of Penzance, Frederic, born on February 29, was apprenticed to a band of pirates until his 21st birthday, in theory until he was 88 years old (as his lifetime included a non-leap centennial year).
This day may be colloquially termed a leap day, though in the Roman calendar it was February 24 in a leap year which was added, giving the name of "bissextile" day or extra sixth day in the lead up to the 'Kalends' of March. The Romans, realizing the need for an extra day, chose February 24 in particular only because it followed the last day of their year, which at that point in history was February 23. An English law of 1256 decrees that in leap years the leap day and the day before are to be reckoned as one day for the purpose of calculating when a full year has passed; thus, in England and Wales a person born on February 29 legally reaches the age of 18 or 21 on February 28 of the relevant year. In the European Union, February 29 only officially became the leap day in 2000.
There is a quaint tradition that women may make a proposal of marriage to men only on February 29; this is a tightening of an older tradition that such proposals may only occur in leap years. In 1288 the Scottish parliament legislated that any woman could propose in Leap Year. Another component of this tradition was that if the man rejects the proposal, he should soften the blow by providing a kiss, one pound currency and a pair of gloves (some later sources say a silk gown). There were similar notions in France and Switzerland.
In France, there is a humorous periodical called La Bougie du Sapeur (the Sapper's Candle) published every February 29 since 1980. The name is a reference to the sapper Camembert. In 2004, the seventh number of La Bougie du Sapeur, subtitled Dimanche, was published. The eighth issue will be published in 2008.
- 1504 - Christopher Columbus uses his knowledge of a lunar eclipse that night to convince Native Americans to provide him with supplies.
- 1704 - Queen Anne's War: French forces and Native Americans attack and destroy Deerfield, Massachusetts, killing 100 men, women, and children.
- 1712 - February 29 is followed by February 30 in Sweden, in a move to abolish the Swedish calendar for a return to the Old style.
- 1720 - Queen Ulrika Eleonora of Sweden abdicates in favour of her husband, who becomes King Frederick I.
- 1864 - American Civil War: Kilpatrick-Dahlgren raid fails - Plans to free 15,000 Union soldiers being held near Richmond, Virginia are thwarted.
- 1892 - St. Petersburg, Florida incorporated.
- 1916 - Child labor: In South Carolina, the minimum working age for factory, mill, and mine workers is raised from twelve to fourteen years old.
- 1932 - TIME magazine features eccentric American politician William "Alfalfa" Murray on its cover after Murray stated his intention to run for President of the United States.
- 1936 - Baby Snooks, played by Fanny Brice, debuts on the radio program The Ziegfeld Follies of the Air.
- 1940 - For her role as Mammy in Gone with the Wind, Hattie McDaniel becomes the first African American to win an Academy Award.
- 1940 - Finland initiates Winter War peace negotiations
- 1940 - In a ceremony held in Berkeley, California, due to the war, physicist Ernest Lawrence receives his 1939 Nobel Prize in Physics from the Sweden's Consul General in San Francisco.
- 1944 - World War II: The Admiralty Islands are invaded in the American General Douglas MacArthur-led Operation Brewer.
- 1952 - The island of Heligoland is restored to German authority.
- 1956 - U.S. President Dwight D. Eisenhower announces to the nation that he is running for a second term. (He defeats Adlai Stevenson that November 6, in a rematch of the 1952 election.)
- 1960 - An earthquake in Morocco kills over 3,000 people and nearly destroys Agadir in the southern part of the country.
- 1964 - In Sydney, Australian swimmer Dawn Fraser sets a new world record in the 100-meter freestyle swimming competition (58.9 seconds).
- 1972 - Vietnam War: Vietnamization - South Korea withdraws 11,000 of its 48,000 troops from Vietnam.
- 1972 - Hank Aaron becomes the first player in the history of Major League Baseball to sign a $200,000 contract.
- 1984 - Canadian Prime Minister Pierre Trudeau announces he will retire as soon as the Liberals can elect another leader.
- 1988 - South African archbishop Desmond Tutu is arrested along with 100 clergymen during a five-day anti-apartheid demonstration in Cape Town
- 1996 - Novelist Joan Collins awarded US $1 million from Random House for breach of contract.
- 1996 - A Peruvian Boeing 737 crashes in the Andes, killing 123 people.
- 2000 - Six year old Dedrick Owens shoots and kills Kayla Rolland, also six years old, at Theo J. Buell Elementary School in Mount Morris Township, Michigan. Rolland is currently the youngest victim of a school shooting 
- 2004 - Jean-Bertrand Aristide resigns as President of Haiti following popular rebel uprising.
- 2004 - The Lord of the Rings: The Return of the King wins the Best Picture Oscar, along with 10 other awards, at the 76th Annual Academy Awards.
For legal purposes, their legal birthdays depend on how different laws count time intervals. In Taiwan, for example, the legal birthday of a leapling is 28 February in common years, so a Taiwanese leapling born on 29 February 1980 (example) would have legally reached 18 years old on 28 February 1998.
"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.<ref>Article 121 of the Civil Code Part I General Principles of the Republic of China in effect in Taiwan</ref>"
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 the Gilbert and Sullivan operetta The Pirates of Penzance.
- 1468 - Pope Paul III (d. 1549)
- 1692 - John Byrom, English poet (d. 1763)
- 1736 - Ann Lee, American founder of Shakers (d. 1784)
- 1792 - Gioacchino Rossini, Italian composer (d. 1868)
- 1840 - John Philip Holland, Irish inventor (d. 1914)
- 1852 - Frank Gavan Duffy, Australian judge (d. 1936)
- 1860 - Herman Hollerith, American statistician (d. 1929)
- 1896 - Morarji Desai, Prime Minister of India (d. 1995)
- 1896 - William A. Wellman, American film director (d. 1975)
- 1904 - Jimmy Dorsey, American bandleader (d. 1957)
- 1904 - Pepper Martin, baseball player (d. 1965)
- 1904 - Rukmini Devi Arundale, Indian dancer and founder of Kalakshetra (d. 1986)
- 1908 - Balthus, French-Polish painter (d. 2001)
- 1908 - Dee Brown, American writer (d. 2002)
- 1908 - Alf Gover, English cricketer (d. 2001)
- 1916 - Dinah Shore, American singer (d. 1994)
- 1920 - Arthur Franz, American actor (d. 2006)
- 1920 - James Mitchell, American actor
- 1920 - Michèle Morgan, French actress
- 1920 - Howard Nemerov, American poet (d. 1991)
- 1924 - Al Rosen, American baseball player
- 1924 - Carlos Humberto Romero, President of El Salvador
- 1928 - Joss Ackland, English actor
- 1928 - Tempest Storm, American burlesque performer
- 1932 - Jaguar, Brazilian cartoonist
- 1936 - Jack Lousma, astronaut
- 1936 - Henri Richard, Canadian hockey player
- 1936 - Alex Rocco, American actor
- 1940 - Patriarch Bartholomew I of Constantinople
- 1944 - Phyllis Frelich, American actress
- 1944 - Dennis Farina, American actor
- 1944 - Paolo Eleuteri Serpieri, Italian illustrator
- 1944 - Ene Ergma, Estonian politician
- 1952 - Sharon Dahlonega Raiford Bush, American television's first African-American primetime weather anchor.
- 1952 - Tim Powers, American writer
- 1952 - Raisa Smetanina, Russian cross-country skier
- 1952 - Bart Stupak, American politician
- 1956 - Jonathan Coleman, Anglo-Australian entertainer
- 1956 - Bob Speller, Canadian politician
- 1956 - Aileen Wuornos, American serial killer (d. 2002)
- 1956 - J. Randy Taraborrelli, American celebritiy journalist
- 1960 - Ian McKenzie Anderson, British musician
- 1960 - Richard Ramirez, American serial killer
- 1960 - Tony Robbins, American motivational speaker
- 1964 - Lyndon Byers, Canadian hockey player
- 1968 - Chucky Brown, American basketball player
- 1968 - Pete Fenson, American curler
- 1968 - Naoko Iijima, Japanese actress
- 1968 - Gonzalo Lira, Chilean-American novelist
- 1968 - Bryce Paup, American football player
- 1972 - Antonio Sabàto, Jr., Italian-born actor
- 1972 - Dave Williams, American singer (Drowning Pool) (d. 2002)
- 1972 - Pedro Zamora, Cuban-born American AIDS activist (d. 1994)
- 1976 - Ja Rule, American rapper and actor
- 1980 - Patrick Côté, Canadian mixed martial artist
- 1980 - Simon Gagné, Canadian hockey player
- 1980 - Taylor Twellman, American soccer player
- 1984 - Darren Ambrose, English footballer
- 1984 - Cam Ward, Canadian hockey player
- 1528 - Patrick Hamilton, Scottish religious reformer (martyred) (b. 1504)
- 1592 - Alessandro Striggio, Italian composer (b. 1540)
- 1604 - John Whitgift, Archbishop of Canterbury (b. 1530)
- 1740 - Pietro Ottoboni, Italian cardinal (b. 1667)
- 1744 - John Theophilus Desaguliers, French philosopher (b. 1683)
- 1820 - Johann Joachim Eschenburg, German literary critic (b. 1743)
- 1868 - Ludwig I of Bavaria (b. 1786)
- 1928 - Ina Coolbrith, first poet laureate of California (b. 1841)
- 1940 - Edward Frederic Benson, American writer (b. 1867)
- 1944 - Pehr Evind Svinhufvud, President of Finland (b. 1861)
- 1956 - Elpidio Quirino, President of the Philippines (b. 1890)
- 1968 - Tore Ørjasæter, Norwegian poet (b. 1886)
- 1980 - Gil Elvgren, American artist (b. 1914)
- 1992 - Ruth Pitter, English poet (b. 1897)
- 2000 - Kayla Rolland, homicide victim (b. 1993)
- 2004 - Jerome Lawrence, American playwright (b. 1915)
Holidays and observances
- Bahá'í Faith - Day 4 of Ayyám-i-Há (Intercalary Days) (in leap years only) - days in the Bahá'í calendar devoted to service and gift giving.
- Discordianism - St. Tib's Day.
- February 29 (Eastern Orthodox liturgics)
February 29, 1900
This day never actually occurred on the Gregorian calendar, since 1900 is not a leap year. However, it is valid according to the Julian calendar, and is recognized as "regular" day in some computer programs, such as Lotus 1-2-3, then eventually in Microsoft Excel (for compatibility reasons).
- Superman's traditional day of birth in the DC universe (due to the nature of comic book stories the year would remain inconsistent). This is a traditional approach many writers take to explain their characters' slow or lack of aging.
- Honor Society of Leap Year Day Babies
- BBC: On This Day
- The New York Times: On This Day
- On This Day in Canada
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