A new stamp of Nelson Mandela is unveiled during a United Nations General Assembly event on the occasion of Mandela Day at the UN headquarters in New York, on July 18, 2018. UN Secretary-General Antonio Guterres on Wednesday called on the world to draw inspiration from former South African President Nelson Mandela to build a better future. Mandela Day, or Nelson Mandela International Day, is an annual international day in honor of Nelson Mandela, celebrated on July 18, his birthday. This year marks the centenary of Mandela's birth. (Xinhua/Li Muzi)