On which day did the attempted coup d'etat of 1991 in the Soviet Union begin?

The attempted coup d'état of 1991 in the Soviet Union began on August 19th, as this was the day when a group of hardline Communist Party members, known as the State Emergency Committee, started their attempt to overthrow Soviet President Mikhail Gorbachev. They aimed to reverse his liberal reforms and halt the country's transition towards democracy. The coup leaders detained Gorbachev while imposing a state of emergency and attempting to take control of key government institutions. However, their coup ultimately failed due to widespread popular opposition, particularly in Moscow.