Cosmonautics Day (Russian: День Космона́втики, romanized: Den' Kosmonávtiki) is an anniversary celebrated in Russia and some other post-Soviet states on 12 April.

Moscow and other cities in the USSR held mass demonstrations, the scale of which was second only to World War II Victory Parades.

Participants then proceed under police escort to Red Square for a visit to Gagarin's grave in the Kremlin Wall Necropolis, and continue to Cosmonauts Alley, near the Monument to the Conquerors of Space.

[3] In the 1960s, the song 14 минут до старта ("14 Minutes Until Start") written by Oscar Feltsman and Vladimir Voynovich was considered the unofficial "anthem of cosmonautics" and regularly aired on this day in the USSR.

In the 1980s, it was eclipsed by the hit Трава у дома ("Grass by the Home") performed by the Russian VIA band Zemlyane ("The Earthlings").