Wikipedia:Selected anniversaries/March 20
March 20: March Equinox (05:48 UTC, 2008); International Earth Day, Norouz in Iran and various Central Asian countries and in Zoroastrianism (2008); Mawlid (Sunni Islam, 2008); Fast of Esther begins at dawn (Judaism, 2008); Purim begins at sundown (Judaism, 2008); Maundy Thursday (Western Christianity, 2008); Independence Day in Tunisia.
- 1852 – Uncle Tom's Cabin, a novel by American author Harriet Beecher Stowe (pictured) about slavery in the United States before the Civil War, was first published.
- 1883 – Eleven countries signed the Paris Convention for the Protection of Industrial Property, one of the first intellectual property treaties.
- 1987 – The antiretroviral drug zidovudine (AZT) became the first antiviral medication approved for use against HIV and AIDS.
- 1995 – The Aum Shinrikyo sect carried out a poison gas attack on the Tokyo Subway, killing 12 people and injuring thousands of others with sarin.