2016-02-21 is International Mother Language Day. The Director General of UNESCO has published her annual message for the day. In it she stresses the importance of mother languages and local languages.More information at: wikipedia and at linguistic-rights.org
and at timeanddate.com which says:
"On International Mother Language Day the UN's Educational, Scientific and Cultural Organization (UNESCO) and UN agencies participate in events that promote linguistic and cultural diversity. They also encourage people to maintain their knowledge of their mother language while learning and using more than one language."