Inventors' Day is observed in Argentina every September 29 to honor the contributions of inventors and innovators, particularly László Bíró, who invented the modern ballpoint pen. Bíró, born in Hungary in 1899, created the ballpoint pen in 1931 to address his frustrations with fountain pens. After fleeing to Argentina during World War II, he and his brother filed a U.S. patent for their invention in 1943 and established Biro Pens of Argentina. The day celebrates not only Bíró's legacy but also recognizes the achievements of outstanding inventors, scientists, engineers, and technologists in the country. The first celebration of Argentine Inventors' Day took place in 1986, the year following Bíró's death in Buenos Aires.