The 2015 International Day of the World's Indigenous Peoples is on the 9th of August. The UN will have programs to celebrate the day on the 10th at UN headquarters in New York. Details are here on the web page of the Permanent Forum on Indigenous Issues.
This year's theme is "Health and Well-being".
The observance of the International Day of the World’s Indigenous Peoples at UN Headquarters will take place on Monday, 10 August 2015, in the ECOSOC Chamber, from 3:00 p.m. to 6:00 p.m. The event will be webcast live on webtv.un.org.