The Universal Children’s Day, first proclaimed by the United Nations General Assembly in 1954, was established to encourage all countries to institute a day, firstly to promote mutual exchange and understanding among children and secondly to initiate action to benefit and promote the welfare of the world’s children. It was also chosen as the day to celebrate childhood and is celebrated annually.
November 20 is also the anniversary of the day when the United Nations General Assembly adopted the Declaration of the Rights of the Child in 1959. The Convention on the Rights of the Child was then signed on the same day in 1989, which has since been ratified by 191 countries. (from http://www.cute-calendar.com)