Here's a brief history about children's day from wikipedia....

Children's Day was begun on the second Sunday of June in 1856 by Reverend Dr. Charles Leonard, pastor of the Universalist Church of the Redeemer in Chelsea, Massachusetts: Dr. Leonard held a special service dedicated to, and for the children. Dr. Leonard named the day Rose Day, though it was later named Flower Sunday, and then Children's Day.

Children's Day was first officially declared a national holiday by the Republic of Turkey in 1929 with the set date of 23 April. Children's Day has been celebrated nationally since 1923 with the government and the newspapers of the time declaring it a day for the children. However, it was decided that an official declaration was needed to clarify and justify this celebration and the official declaration was made nationally in 1931 by the founder and the President of the Republic of Turkey, Mustafa Kemal Atatürk.

The International Day for Protection of Children is observed in many countries as Children's Day on 1 June since 1950. It was established by the Women's International Democratic Federation on its congress in Moscow (4 November 1949).[citation needed] Major global variants include a Universal Children's Holiday on 20 November, by United Nations recommendation.

Universal Children's Day takes place annually on 20 November. First proclaimed by the United Kingdom in 1954, it 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.

That is observed to promote the objectives outlined in the Charter and for the welfare of children. On 20 November 1959 the United Nations adopted the Declaration of the Rights of the Child. The United Nations adopted the Convention on the Rights of the Child on 20 November 1989 and can be found on the Council of Europe website. (www.wiki.com)