UNITED NATIONS, April 17 -- The United Nations celebrated its fifth Chinese Language Day here Thursday with a series of special activities to highlight the historical and cultural importance of the Chinese language.

"The United Nations Chinese Language Day was established by the UN Educational, Scientific and Cultural Organization (UNESCO) in 2010 to celebrate multilingualism and cultural diversity, as well as to promote equal use of all six of its official working languages throughout the organization," said Heather Landon, Director of Documentation Division of the UN Conference Department, in a speech at a ceremony marking the Day.

Calling the linguistic study of the Chinese language "a fascinating challenge," Landon said she is amazed that the history of the Chinese language encompasses "an impressive variety", "which includes the many dialects and variations of the language in China and surrounding geographic areas."

Except for her, dozens of UN staff members and diplomats from different countries gathered at the Secretariat Building in the UN headquarters to enjoy a host of events.

As part of the celebration, an exhibition of Chinese calligraphy and paintings was held at the UN headquarters in New York on April 14-17. Fo Tao, a master calligrapher from Beijing, gave a workshop here Thursday on how to learn Chinese calligraphy.

Other events included lectures, tea art and musical performance. Some UN staff members of different national backgrounds, who are also participants of a UN Chinese program, even surprised the audience by singing several well-known Chinese popular songs.

The celebration is held around the same time in April each year on Guyu, or literally meaning "Rain of Millet", which is the sixth of the 24 solar terms created by ancient Chinese to carry out agricultural activities, to pay tribute to Cangjie -- an ancient Chinese mythical figure who is credited with having invented Chinese characters about 5,000 years ago.

Chinese is one of the six official languages of the world body along with French, Spanish, Russian, English and Arabic. The Chinese language is now spoken by more than a billion people, which means one in seven people communicate with Chinese in the world.