Events January January 15 – The Moon moves into its nearest point to Earth, called perigee, at the same time as its fullest phase of the Lunar Cycle. This is the closest moon distance at in recent history, and the next one will be on January 1, 2257, at . January 26 – The Indian National Congress declares this date as Independence Day, or as the day for Poorna Swaraj (Complete Independence). January 28 – The first patent for a field-effect transistor is granted in the United States, to Julius Edgar Lilienfeld. January 30 – Pavel Molchanov launches a radiosonde from Slutsk in the Soviet Union. February February 10 – The Việt Nam Quốc Dân Đảng launch the Yên Bái mutiny in the hope of ending French colonial rule in Vietnam. February 18 – While studying photographs taken in January, Clyde Tombaugh confirms the existence of Pluto, a celestial body considered a planet until redefined as a dwarf planet in 2006. March March 2 Mahatma Gandhi informs the British Viceroy of India that civil disobedience will begin the following week. André Tardieu begins his second term as Prime Minister of France. March 6 International Unemployment Day is observed in countries throughout the world. The first frozen foods of Clarence Birdseye go on sale in Springfield, Massachusetts. March 12 – Mahatma Gandhi sets off on a 200-mile protest march towards the sea with 78 followers, to protest against the British monopoly on salt; more will join them during the Salt March that ends on April 5. March 28 – The government of Turkey requests the international community to adopt Istanbul and Ankara, as the official names for Constantinople and Angora. The U.S. State Department adopts the "Istanbul" form in May. March 29 – Heinrich Brüning is appointed Chancellor of Germany. March 31 – The Motion Picture Production Code ("Hays Code") is instituted in the United States, imposing strict guidelines on the treatment of sex, crime, religion and violence in films for the next 40 years. April April 6 In an act of civil disobedience, Mahatma Gandhi breaks the salt laws of British India by making salt by the sea at the end of the Salt March. The International Left Opposition (ILO) is founded in Paris, France. April 17 – Neoprene is invented by DuPont. April 18 – The Chittagong Rebellion begins in India, with the Chittagong armoury raid. April 21 A