May 17, 2016 Ryan Roemerman LGBT History, Laws and Policies, Global LGBT Rights How the world is celebrating International Day against Homophobia, Transphobia, and Biphobia May 17, 2016 Ryan Roemerman LGBT History, Laws and Policies, Global LGBT Rights IDAHOT is celebrated annually on 17 May to commemorate WHO's decision to declassify homosexuality as a mental disorder in 1990. IDAHOT was created in 2004 and is now celebrated in more than 120 countries, whether in triumph or in defiance.