International Mother Language Day is an observance held annually on 21 February worldwide to promote awareness of linguistic and cultural diversity and multilingualism. It was first announced by UNESCO on 17 November 1999. Its observance was also formally recognized by the United Nations General Assembly in its resolution establishing 2008 as the International Year of Languages.
Languages are the most powerful instruments of preserving and developing our tangible and intangible heritage. All moves to promote the dissemination of mother tongues will serve not only to encourage linguistic diversity and multilingual education but also to develop fuller awareness of linguistic and cultural traditions throughout the world and to inspire solidarity based on understanding, tolerance and dialogue.
—from the United Nations International Mother Language Day