April 1 belongs to Montse Coll

April 1 is April Fools' Day in English-speaking countries and many others around the world. The origin of this tradition of pranks and hoaxes is uncertain; some theories link it to the switch from the Julian to the Gregorian calendar in the sixteenth century, when those who still celebrated New Year in April were mocked. The custom spread globally and today inspires everything from private pranks to viral campaigns by the world's largest companies.

On April 1, 1979, Ayatollah Khomeini proclaimed the Islamic Republic of Iran following the referendum in which 98% of Iranians voted in favour of the new form of government. The proclamation — the day the first Islamic republic of the twentieth century was formally established — was the culminating point of the Iranian Revolution that had toppled Shah Mohammad Reza Pahlavi months earlier.

On April 1, 1976, Steve Jobs, Steve Wozniak and Ronald Wayne founded Apple Computer Company in Jobs's parents' garage in Los Altos, California. The first product was the Apple I, a computer hand-assembled by Wozniak. In four decades, Apple became the most valuable company in history, surpassing one trillion dollars in market capitalisation in 2018.