Mexico celebrates Teacher’s Day on May 15. According to Gaceta UNAM, the decree that created it was published on December 3, 1917, and the day was first celebrated in 1918. México Desconocido describes its rules. Classes “debían suspenderse” (were to be suspended), and “tenían que organizarse actividades en todas las escuelas para destacar la labor de los profesores” (activities had to be organized in all schools to highlight the work of the teachers).