April 1st

Benjamin Netanyahu took office as Israel's prime minister for a second time.
Benjamin Netanyahu
The Pentagon made public a legal memo dated March 14, 2003, that approved the use of harsh interrogation techniques against terror suspects.
Enhanced interrogation techniques
American troops rescued Army Pfc. Jessica Lynch from a hospital in Nasiriyah, Iraq, where she had been held prisoner since her unit was ambushed nine days earlier.
Jessica Lynch
Slobodan Milošević is arrested. The former President of Serbia was arrested on corruption charges. Later he was put on trial before the International Criminal Tribunal for the former Yugoslavia (ICTY) in The Hague for war crimes during the Yugoslav wars.
Slobodan Milošević
A New Jersey man was arrested and charged with originating the "Melissa" e-mail virus, which infected more than 1 million computers worldwide.
Timeline of computer security hacker history
In his first major speech on the epidemic, President Ronald Reagan told doctors in Philadelphia, "We've declared AIDS public health enemy No. 1.".
Domestic policy of the Ronald Reagan administration
Singer Marvin Gaye, 44, was shot to death by his father.
Death of Marvin Gaye
Ayatollah Khomeini proclaimed Iran to be an Islamic Republic.
Ruhollah Khomeini
Apple Inc. is founded. The computer company, which has evolved into a multinational corporation and whose best-known product is the iPhone, was founded by Steve Jobs, Steve Wozniak, and Ronald Wayne. In 2012, the company's global revenue amounted to $156 billion.
Apple Inc.
Ayatollah Khomeini calls for an Islamic Republic in Iran.
History of the Islamic Republic of Iran
President Nixon signed a bill into law banning cigarette ads from radio and television.
Public Health Cigarette Smoking Act
The daytime soap opera General Hospital first aired on ABC-TV.
General Hospital
The first weather satellite, TIROS-1, was launched from Cape Canaveral.
The BBC broadcasts the spaghetti tree hoax. The 3-minute film shown on the current affairs program, Panorama, portrayed a Swiss family apparently harvesting spaghetti from a tree. A number of viewers later contacted the BBC to inquire where to find and how to grow such a plant. The hoax is regarded as one of the best April Fools jokes ever pulled.
Spaghetti-tree hoax
Big Bang theory proposed in Physical Review by Alpher, Bethe & Gamow.
Alpher–Bethe–Gamow paper
American forces landed on Okinawa during World War II.
Battle of Okinawa
General Franco proclaims victory in the Spanish civil war. The dictator ruled Spain until his death in 1975. His regime was responsible for gross human rights violations, including murdering numerous political opponents.
Spanish Civil War
The Nazi persecution of Jews began in Germany with a boycott of Jewish businesses.
Nazi boycott of Jewish businesses
Britain's Royal Air Force was established.
History of the Royal Air Force
Composer Sergei Rachmaninoff was born in Russia.
Sergei Rachmaninoff
Cincinnati, Ohio, became the first U.S. city to pay its firefighters a regular salary.
Frederick Muhlenberg of Pennsylvania was elected the first Speaker of the House of Representatives.
Frederick Muhlenberg
Oliver Pollack created the dollar sign: $.
Oliver Pollock
Ruins of Pompeii rediscovered by Spaniard Rocque Joaquin de Alcubierre.
Roque Joaquín de Alcubierre
Byzantine Emperor Justin I names his nephew Justinian I as co-ruler and successor to the throne.
Justinian I