Suit. Children's Day is a festival for children. Boys should dress appropriately. Wearing a suit is a more formal dress, which enhances your temperament and is very sexy, and it is easy to leave a safe impression on others. The origin of Children's Day on June 1st. International Children's Day is scheduled for June 1 every year. In memory of the Lidice tragedy on June 1942 and all the children who died in the war all over the world.