The World Conference for the Well-being of Children, held in Geneva in 1925, proclaimed June 1 to be International Children's Day. It is unclear why this date was chosen, but it is believed that China's consul general in San Francisco gathered together many Chinese orphans on the day of the conference to celebrate the Dragon Boat Festival.
Irene Chan Man-tuen, chief executive of the Hong Kong Committee for Unicef, said teenagers in Hong Kong have become more actively involved in helping other less-fortunate teenagers in the past few years.
Besides giving donations, they contact the children's charity, Unicef, to look for work as volunteers.
"Nothing is more important and encouraging than children helping other children," Chan said. "This kind of help is more sustainable - not just a one-off."
Up to 40 Unicef young envoys will visit poor villages on the mainland this summer to learn about the lives of the children there. It is part of the organisation's sustainable campaign to allow children to help their contemporaries in other countries. Ma Wing-yin, a Form Five student at St Rose of Lima's College, Sha Tin, organised a hunger banquet in March to raise money for children in developing countries.
She said she wanted her schoolmates to treasure everything they have because many children in poor countries have a very difficult time.
About 150 students took part in the banquet. Each of them was randomly given a ticket indicating whether they would be "rich" or "poor". The "rich" were given pizzas to eat for lunch while the "poor" were offered only three pieces of bread and a bottle of water.
With each student paying HK$10 for a ticket, Ma raised HK$1,500.
Meanwhile, inspired by Cathay Pacific airline's Change for Good fund-raising programme, which collects the spare foreign currency of passengers, students at Li Po Chun United World College, in Sha Tin, carried out a similar scheme in March.
About HK$1,700 was raised after they put donation boxes throughout the campus into which students could donate loose change. They even distributed leaflets around the campus and set up a Facebook fan page to promote the campaign.
Student organisers said the college has students from about 100 countries, so coins from many different nations were collected. This campaign raised awareness about less-fortunate children in other countries.
In a separate campaign, students at Pui Ching Middle School, in Ho Man Tin, held a fund-raising concert in March. The event, featuring students playing music in various bands, attracted an audience of 200 students and teachers and raised HK$5,000. All of the money raised was donated to Unicef.