The International Day for the Abolition of Slavery is a yearly event on December 2, organized by the United Nations General Assembly. The Day was first celebrated in 1986.
The Convention for the Suppression of the Traffic in Persons and of the Exploitation of the Prostitution of Others was approved by the United Nations General Assembly on December 2, 1949. Besides, by resolution 57/195 of 18 December 2002, the Assembly proclaimed 2004 the International Year to Commemorate the Struggle against Slavery and its Abolition.
(Ref: https://en.wikipedia.org/wiki/International_Day_for_the_Abolition_of_Slavery & ANTI-SLAVERY DAY)