It is the midpoint of a common year. This is because there are 182 days before and 182 days after (median of the year) in common years, and 183 before and 182 after in leap years. The exact time in the middle of the year is at noon, or 12:00 pm.
It falls on the same day of the week as New Year's Day in common years.

Events

• 626 – In fear of assassination, Li Shimin ambushes and kills his rival brothers Li Yuanji and Li Jiancheng in the Incident at Xuanwu Gate. On September 4, Shimin's father abdicates in his favour and Shimin becomes Emperor Taizong of Tang, Emperor of China.

• 706 – In China, Emperor Zhongzong of Tang has the remains of Emperor Gaozong of Tang, his wife and recently-deceased ruling empress Wu Zetian, her son Li Xian, her grandson Li Chongrun, and granddaughter Li Xianhui all interred in a new tomb complex outside Chang'an known as the Qianling Mausoleum, located on Mount Liang.

• 963 – The imperial army proclaims Nicephorus Phocas to be Emperor of the Romans on the plains outside Cappadocian Caesarea.

• 1298 – The Battle of Göllheim is fought between Albert I of Habsburg and Adolf of Nassau-Weilburg.

• 1494 – The Treaty of Tordesillas is signed by Portugal and Spain.

• 1555 – Turgut Reis sacks the Italian city of Paola.

• 1561 – Menas, Emperor of Ethiopia, defeats a revolt in Emfraz.

• 1582 – Battle of Yamazaki: Toyotomi Hideyoshi defeats Akechi Mitsuhide.

• 1613 – The first English expedition from Massachusetts against Acadia led by Samuel Argall.

• 1644 – English Civil War: the Battle of Marston Moor.

• 1679 – Europeans first visit Minnesota and see headwaters of Mississippi in an expedition led by Daniel Greysolon de Du Luth.

• 1698 – Thomas Savery patents the first steam engine.

• 1776 – The Continental Congress adopts a resolution severing ties with Great Britain although the wording of the formal Declaration of Independence is not approved until July 4.

• 1777 – Vermont becomes the first American territory to abolish slavery.

• 1823 – Bahia Independence Day: the end of Portuguese rule in Brazil, with the final defeat of the Portuguese crown loyalists in the province of Bahia.

• 1839 – Twenty miles off the coast of Cuba, 53 rebelling African slaves led by Joseph Cinque take over the slave ship Amistad.

• 1850 – The self-contained gas mask is patented by Benjamin J. Lane.

• 
  *1863 – American Civil War: second day of the Battle of Gettysburg.

• 1870 – Jules Joseph d'Anethan is elected the tenth Prime Minister of Belgium.

• 1871 – Victor Emmanuel II of Italy enters Rome after its conquest from the Papal States.

• 1881 – Charles J. Guiteau shoots and fatally wounds U.S. President James Garfield, who eventually dies from an infection on September 19.

• 1890 – The U.S. Congress passes the Sherman Anti-Trust Act.

• 1897 – Italian scientist Guglielmo Marconi obtains patent for radio in London.

• 1900 – First zeppelin flight takes place on Lake Constance near Friedrichshafen, Germany.

• 1917 – The East St. Louis Riots end.

• 1934 – The Night of the Long Knives ends with the death of Ernst Röhm.

• 1937 – Amelia Earhart and navigator Fred Noonan are last heard from over the Pacific Ocean while attempting to make the first equatorial round-the-world flight.

• 1940 – Indian independence leader Subhas Chandra Bose is arrested and detained in Calcutta.

• 1950 – The Golden Pavilion at Kinkaku-ji in Kyoto, Japan burns down.

• 1962 – The first Wal-Mart store opens for business in Rogers, Arkansas.

• 1964 – President Lyndon B. Johnson signs the Civil Rights Act of 1964 meant to prohibit segregation in public places.

• 1966 – The French military explodes a nuclear test bomb codenamed Aldébaran in Mururoa, their first nuclear test in the Pacific.

• 1976 – North and South Vietnam, divided since 1954, reunite to form the Socialist Republic of Vietnam.

• 1979 – The first U.S. coin to honor a woman, the Susan B. Anthony dollar, is introduced.

• 1985 – Andrei Gromyko is appointed the chairman of the Presidium of the Supreme Soviet of the Soviet Union.

• 1987 – Nilde Iotti is named as the first female President of the Italian Chamber of Deputies.

• 1993 – 37 participants in an Alevi cultural and literary festival were killed when a mob of demonstrators set fire to their hotel in Sivas during a violent protest.

• 2000 – Vicente Fox Quesada is elected the first President of México from an opposition party, the Partido Acción Nacional, after more than 70 years of continuous rule by the Partido Revolucionario Institucional.

• 2001 – The AbioCor self contained artificial heart is first implanted.

• 2002 – Steve Fossett becomes the first person to fly solo around the world nonstop in a balloon.

• 2003 – Silvio Berlusconi, Prime Minister of Italy, insults German MP Martin Schulz by calling him a "kapo" during a session of the European Parliament.

• 2004 – ASEAN Regional Forum accepts Pakistan as its 24th member.¨

• 2005 – Live 8 takes place in London's Hyde Park and other locations around the world.

• 2008 – Ingrid Betancourt, and 14 other hostages held by FARC guerrillas, are rescued by the Colombian armed forces.

Births

• 419 – Valentinian III, Roman Emperor (d. 455)

• 1029 – Caliph Al-Mustansir of Cairo (d. 1094)

• 1262 – Arthur II, Duke of Brittany (d. 1312)

• 1363 – Mary, Queen of Sicily (d. 1401)

• 1489 – Thomas Cranmer, Archbishop of Canterbury (d. 1556)

• 1492 – Elizabeth Tudor, English princess (d. 1495)

• 1647 – Daniel Finch, 2nd Earl of Nottingham, English privy councilor (d. 1730)

• 1665 – Samuel Penhallow, English-born American colonist and historian (d. 1726)

• 1667 – Pietro Ottoboni, Italian cardinal (d. 1740)

• 1698 – Francesco III d'Este, Duke of Modena (d. 1780)

• 1714 – Christoph Willibald von Gluck, German composer (d. 1787)

• 1724 – Friedrich Gottlieb Klopstock, German poet (d. 1803)

• 1819 – Charles-Louis Hanon, French composer (d. 1900)

• 1820 – George Law Curry, Newspaper publisher and Governor of Oregon (d. 1878)

• 1821 – Charles Tupper, sixth Prime Minister of Canada (d. 1915)

• 1849 – Maria Theresia of Austria-Este, queen of Bavaria (d. 1919)

• 1862 – William Henry Bragg, English physicist, Nobel laureate (d. 1942)

• 1865 – Lily Braun, German writer (d. 1916)

• 1876 – Wilhelm Cuno, Chancellor of Germany (d. 1933)

• 1877 – Hermann Hesse, German-born writer, Nobel laureate (d. 1962)

• 1881 – Royal H. Weller, American politician (d. 1929)

• 1884 – Alfons Maria Jakob, German neurologist (d. 1931)

• 1893 – Ralph Hancock, Welsh garden designer (Rockefeller Center) (d. 1950)

• 1896 – Lydia Mei, Estonian artist (d. 1965)

• 1900 – Tyrone Guthrie, English actor (d. 1971)

• 1903 – Alec Douglas-Home, Prime Minister of the United Kingdom (d. 1995)

• 1903 – King Olav V of Norway (d. 1991)

• 1904 – René Lacoste, French tennis player (d. 1996)

• 1906 – Hans Bethe, German-born nuclear physicist, Nobel laureate (d. 2005)

• 1908 – Thurgood Marshall, American Supreme Court Justice (d. 1993)

• 1914 – Frederick Fennell, American conductor (d. 2004)

• 1914 – Mário Schenberg, Brazilian physicist (d. 1990)

• 1915 – Arthur Wellesley, 8th Duke of Wellington

• 1916 – Ken Curtis, American actor and singer (d. 1991)

• 1916 – Hans-Ulrich Rudel, Combat pilot and highest-decorated German soldier of WWII (d. 1982)

• 1917 – Murry Wilson, American musician and producer (The Beach Boys) (d. 1973)

• 1918 – Wibo, Dutch cartoonist (d. 2005)

• 1919 – Jean Craighead George, American writer

• 1923 – Wisława Szymborska, Polish writer, Nobel laureate

• 1925 – Medgar Evers, American civil rights activist (d. 1963)

• 1925 – Patrice Lumumba, Prime Minister of the Democratic Republic of the Congo (d. 1961)

• 1926 – Octavian Paler, Romanian writer, journalist, (d. 2007)

• 1927 – Brock Peters, American actor (d. 2005)

• 1927 – Gene Ray, Founder of the Time Cube website and proponent of Time Cube philosophy

• 1929 – Imelda Marcos, First Lady of the Philippines

• 1929 – John A. Cade, American politician

• 1930 – Carlos Menem, President of Argentina

• 1932 – Dave Thomas, American fast food entrepreneur (d. 2002)

• 1933 – Kenny Wharram, Canadian hockey player

• 1934 – Tom Springfield, British singer and songwriter (The Springfields)

• 1937 – Polly Holliday, American actress

• 1937 – Richard Petty, American race car driver

• 1939 – John H. Sununu, White House Chief of Staff under George HW Bush

• 1939 – Alexandros Panagoulis, Greek politician and poet

• 1939 – Paul Williams, American singer (The Temptations) (d. 1973)

• 1940 – Kenneth Harry Clarke, British politician

• 1941 – Stéphane Venne, French Canadian songwriter

• 1942 – Vicente Fox, Former Mexican president

• 1943 – Walter Godefroot, Belgian cyclist

• 1946 – Richard Axel, American scientist, Nobel laureate

• 1946 – Ron Silver, American actor (d. 2009)

• 1947 – Larry David, American television producer

• 1948 – Saul Rubinek, Canadian actor

• 1948 – Gene McFadden, American songwriter (d. 2006)

• 1949 – Roy Bittan, American musician (E Street Band)

• 1949 – Hanno Pöschl, Austrian actor

• 1949 – Robert Paquette, French Canadian singer and songwriter

• 1951 – Michele Santoro, Italian TV journalist

• 1951 – Elisabeth Brooks, Canadian actress (d. 1997)

• 1952 – Johnny Colla, American musician (Huey Lewis and the News)

• 1953 – Mark Hart, British musician (Crowded House and Supertramp)

• 1953 – Tony Armas, Venezuelan baseball player

• 1954 – Pete Briquette, Irish musician (The Boomtown Rats)

• 1955 – Andrew Divoff, Venezuelan actor

• 1955 – Kevin Michael Grace, Canadian journalist

• 1956 – Jerry Hall, American actress

• 1957 – Bret "Hitman" Hart, Canadian wrestler

• 1958 – Thomas Bickerton, American Methodist bishop

• 1959 – Mike Hallett, English snooker player

• 1960 – Terry Rossio, American screenwriter

• 1961 – Michael Lindsay, Voice actor

• 1961 – Samy Naceri, French actor

• 1963 – Mark Kermode, British film critic

• 1964 – José Canseco, Cuban-born American baseball player

• 1964 – Ozzie Canseco, Cuban-born American baseball player

• 1964 – Joe Magrane, American baseball player

• 1964 – Charles Robinson, American wrestling referee

• 1964 – Alan Tait, Scotland rugby player

• 1969 – Matthew Cox, American convicted felon

• 1969 – Tim Rodber, England rugby player

• 1970 – Yancy Butler, American actress

• 1970 – Colin Edwin, Australian musician (Porcupine Tree)

• 1970 – Scotty 2 Hotty, American professional wrestler

• 1970 – Monie Love, English rapper

• 1970 – Steve Morrow, Irish footballer

• 1971 – Evelyn Lau, Canadian author

• 1971 – Troy Brown, American football player

• 1971 – Bryan Redpath, Scotland rugby player

• 1972 – Darren Shan, Irish children's author

• 1973 – Peter Kay, British comedian

• 1974 – Sean Casey, American baseball player

• 1974 – Moon So-ri, South Korean actress

• 1974 – Matthew Reilly, Australian author

• 1974 – Rocky Gray, American musician

• 1974 – Tim Christensen, Danish singer

• 1975 – Erik Ohlsson, Swedish guitarist (Millencolin)

• 1975 – Éric Dazé, French Canadian ice hockey player

• 1975 – Stefan Terblanche, South African rugby player

• 1976 – Krisztián Lisztes, Hungarian footballer

• 1976 – Tomáš Vokoun, Czech hockey player

• 1978 – Jüri Ratas, Estonian politician

• 1979 – Diana Gurtskaya, Georgian singer

• 1979 – Sam Hornish, Jr., American race car driver

• 1979 – Joe Thornton, Canadian hockey player

• 1980 – Nicole Manske, American beauty queen and motorsports television commentator

• 1980 – Nyjer Morgan, American baseball player

• 1981 – Nathan Ellington, English footballer

• 1981 – Alex Koroknay-Palicz, American youth rights activist

• 1981 – Angel Pagán, Puerto Rican baseball player

• 1981 – Aaron Voros, Canadian hockey player

• 1982 – Olivia Munn, American actress, model and television personality.

• 1983 – Michelle Branch, American singer (The Wreckers)

• 1983 – Sammy J, Australian comedian

• 1984 – Vanessa Lee Chester, American actress

• 1984 – Thomas Kortegaard, Danish footballer

• 1984 – Johnny Weir, American figure skater

• 1985 – Rhett Bomar, American football player

• 1985 – Chad Henne, American football player

• 1985 – Ashley Tisdale, American actress and singer

• 1986 – Brett Cecil, American baseball player

• 1986 – Lindsay Lohan, American actress and singer

• 1987 – Ruslana Korshunova, Kazakhstani model (d. 2008)

• 1992 – Madison Chock, American ice dancer

Deaths

• 862 – St. Swithun, Bishop of Winchester(b. 789)

• 1298 – Adolf of Nassau, King of Germany (b. 1220)

• 1504 – Ştefan cel Mare, Prince of Moldova (b. 1434)

• 1566 – Nostradamus, French astrologer (b. 1503)

• 1582 – Akechi Mitsuhide, Japanese samurai (b. 1528)

• 1591 – Vincenzo Galilei, Italian composer (b. 1520)

• 1621 – Thomas Harriot, English astronomer

• 1656 – François-Marie, comte de Broglie, Italian-born French commander (b. 1611)

• 1674 – Eberhard III, Duke of Württemberg (b. 1614)

• 1684 – John Rogers, president of Harvard University (b. 1630)

• 1743 – Spencer Compton, 1st Earl of Wilmington, second Prime Minister of the United Kingdom (b. 1673)

• 1746 – Thomas Baker, English antiquarian (b. 1656)

• 1778 – Jean-Jacques Rousseau, Swiss philosopher (b. 1712)

• 1778 – Bathsheba Spooner, American murderer (b. 1746)

• 1822 – Denmark Vesey, American who planned slave revolt, hanged (b. ca. 1767)

• 1833 – Gervasio Antonio de Posadas, Argentine politician (b. 1757)

• 1843 – Samuel Hahnemann, German physician (b. 1755)

• 1850 – Robert Peel, Prime Minister of the United Kingdom (b. 1788)

• 1857 – Carlo Pisacane, Italian patriot (b. 1818)

• 1903 – Ed Delahanty, American Hall of Fame baseball player (b. 1867)

• 1912 – Tom Richardson, English cricketer (b. 1870)

• 1914 – Joseph Chamberlain, Mayor of Birmingham and Father of Neville (b. 1836)

• 1915 – Porfirio Díaz, President of Mexico (b. 1830)

• 1920 – William Louis Marshall, American general and engineer (b. 1846)

• 1926 – Émile Coué, French psychologist (b. 1857)

• 1929 – Gladys Brockwell, American actress (b. 1893)

• 1932 – Manuel II of Portugal (b. 1889)

• 1934 – Ernst Röhm, Nazi official (b. 1887)

• 1955 – Edward Lawson, Scottish recipient of the Victoria Cross (b. 1873)

• 1961 – Ernest Hemingway, Nobel Prize laureate (b. 1899)

• 1964 – Glenn "Fireball" Roberts, American race car driver (b. 1929)

• 1966 – Jan Brzechwa, Polish poet (b. 1900)

• 1969 – Michael DiBiase, wrestler (b. 1923)

• 1972 – Joseph Fielding Smith, tenth president of The Church of Jesus Christ of Latter-day Saints (b. 1876)

• 1973 – Betty Grable, American actress (b. 1916)

• 1973 – Chick Hafey, baseball player (b. 1903)

• 1973 – George McBride, baseball player (b. 1880)

• 1973 – Ferdinand Schörner, German field marshal (b. 1892)

• 1975 – James Robertson Justice, British actor (b. 1907)

• 1977 – Vladimir Nabokov, Russian-born writer (b. 1899)

• 1978 – Aris Alexandrou, Greek novelist, poet and translator (b. 1922)

• 1984 – Paul Dozois, Quebec politician (b. 1908)

• 1985 – David Purley, British Formula 1 driver (b. 1945)

• 1986 – Peanuts Lowrey, baseball player (b. 1917)

• 1989 – Franklin Schaffner, American film director (b. 1920)

• 1989 – Andrei Gromyko, Soviet politician (b. 1909)

• 1991 – Lee Remick, American actress (b. 1935)

• 1992 – Camarón de la Isla, Spanish flamenco singer (b. 1950)

• 1993 – Fred Gwynne, American actor (b. 1926)

• 1993 – Sir Edward Dunlop, Australian war hero (b. 1907)

• 1994 – Andrés Escobar, Colombian footballer (b. 1967)

• 1995 – Krissy Taylor, American model (b. 1978)

• 1997 – James Stewart, American actor (b. 1908)

• 1999 – Mario Puzo, American author (b. 1920)

• 2000 – Joey Dunlop, Irish motorcycle racer (b. 1952)

• 2002 – Ray Brown, American jazz bassist (b. 1926)

• 2004 – Sophia de Mello Breyner Andresen, Portuguese writer (b. 1919)

• 2004 – John Cullen Murphy, American comic strip artist (b. 1919)

• 2005 – Ernest Lehman, American screenwriter (b. 1915)

• 2005 – Norm Prescott, American animation producer (b. 1927)

• 2006 – Jan Murray, American comedian (b. 1916)

• 2007 – Beverly Sills, American operatic soprano (b. 1929)

• 2008 – Natasha Shneider, Russian-born musician (b. 1956)

• 2008 – Elizabeth Spriggs, English-Born Actress (b. 1929)

Holidays and observances

• Bahia: Independence Day

• Curaçao: Flag Day

• Palio di Provenzano in Siena, Italy

• Annual pilgrimage at Mariánska hora

• Saints and martyrs:

• *Aberoh and Atom

• *Saint Bernardino Realino (d. 1616)

• *Saint John Regis

• *Saint Martial

• *Saint Otto, bishop of Bamberg (d. 1139)

• *Saint Oudoceus, bishop of Llandaff

• *Saints Processus and Martinianus, martyrs

• *Saint Swithun, bishop of Winchester, confessor

• *Saint Monegundes, matron, recluse