International Children's Day is observed on June 01, 2018. The World Conference for the Well-being of Children in Geneva, Switzerland, proclaimed June 1 to be International Children's Day in 1925. After the conference, different governments around the world decided to declare a day as Children's Day to draw attention to children's issues. Many countries chose June 1, so this is the reason, why International Children's Day take place an June 1.
The similar Universal Children's Day falls on 20 November 2018. National Children's Days are recognized on various days in many places around the world, to honor children globally. The UN General Assembly recommended that all countries should establish a Universal Children's Day on an "appropriate" day.