August 15th

North Korea Introduces Pyongyang Time. The East Asian country introduced the time change to commemorate the 70th anniversary of the end of the Japanese occupation of Korea. Before the change, North Korea was UTC+09:00. Since this day, the time in the country is UTC+08:30.
Time in North Korea
Astronomers announced the discovery of the first solar system outside our own.
Discoveries of exoplanets
A car bomb in Omagh, Northern Ireland, killed 29 people. It was the deadliest act of violence in more than 30 years of "Troubles.".
Omagh bombing
US involvement in Vietnam ends. The Case–Church Amendment passed by the US Congress set August 15 as the deadline for the end of the US military involvement in Vietnam, Laos, and Cambodia. Because of this, the US ended all military offensives in Vietnam on this day.
Vietnam War
The Woodstock Music & Art Fair opens its doors to participants and spectators. The iconic music festival, popularly known as Woodstock was held in Bethel, New York at the 600-acre farm of farmer Max B. Yasgur. Over 400,000 people attended the festival, which is often thought to be a key moment in the anti-establishment movement that was gaining popularity in the United States.
Congo gains its Independence. The Central African country came under French control in the late 19th century. In the early 20th century, the French consolidated their territories in Central Africa to create the French Equatorial Africa, with Brazzaville as its capital. During the Second World War, when the Nazis occupied France, Brazzaville acted as the temporary capital of Free France. After violent protests and riots, the country became independent with Fulbert Youlou as its first President.
Congo Crisis
South Korea became the Republic of Korea.
History of South Korea
India Becomes Independent From British Rule. British control of the South Asian country began in mid 1800s with the East India Company. The company initially established itself in the subcontinent for trading purposes, and then slowly took control over the princely states that separately ruled the country. A violent rebellion in 1857 prompted the British Crown to take over direct rule of India. The time between then and independence in 1945 was marked by violent and nonviolent movements targeted towards gaining independent rule. Mohandas Karamchand Gandhi was a key figure in the nonviolent civil disobedience movement against the British. Independence came with the country being partitioned into India and Pakistan. Jawaharlal Nehru became the first Prime Minister of India, while Liaquat Ali Khan became the first Prime Minister of Pakistan.
Indian Independence Act 1947
The Wizard of Oz premiered in Hollywood.
The Wizard of Oz (1939 film)
Aviator Wiley Post and actor Will Rogers were killed in a plane crash.
Will Rogers
Proctor & Gamble Company introduced Crisco vegetable shortening.
Fletcher D. Proctor
The Boxer Rebellion: In China, the Empress, her family and court retainers flee while foreign troops move through Peking in an attempt to quell the rebellion.
Mayflower sets sail from Southampton, England, with 102 Pilgrims.
Empire of Trebizond surrenders to forces of Sultan Mehmet II - last Byzantine Empire remnant to fall. Emperor David exiled and later murdered.
Byzantine Empire
Macbeth, king of Scotland, was killed by Malcolm Canmore.
Malcolm III of Scotland