International Day of Human Space Flight
The International Day of Human Space Flight is the annual celebration, held on April 12, of the anniversary of the first human space flight by Yuri Gagarin. It was proclaimed at the 65th session of the United Nations General Assembly on April 7, 2011, a few days before the 50th anniversary of the flight.
In the Soviet Union, April 12 was commemorated as Cosmonautics Day since 1963, and is still observed in Russia and some former Soviet states. Yuri's Night, also known as "World Space Party" is an international observance initiated in the United States in 2001, on the 40th anniversary of Gagarin's flight.