The World Day Against Child Labour is an International Labour Organization (ILO)-sanctioned holiday first launched in 2002  aiming to raise awareness and activism to prevent child labour. It was spurred by ratifications of ILO Convention No. 138 on the minimum age for employment and ILO Convention No. 182 on the worst forms of child labour.
The World Day Against Child Labour, which is held every year on June 12, is intended to foster the worldwide movement against child labour. (Source)