Today I join people around the world in celebrating Nelson Mandela International Day. A personal hero of mine and of countless others, Nelson Mandela was one of the most influential, courageous, and profoundly decent human beings to grace the earth. A dignified warrior for justice and equality, he caused us to believe in the promise of a better world. Today -- Madiba's birthday -- is the first time we have marked this occasion since he left this world late last year, but his impact on our lives remains palpable and his inspiration endures. A humble and committed public servant, Madiba said this day was not to be a holiday, but one devoted to service. It was his hope that people would dedicate their time and effort to improve the conditions within their community, stating there "can be no greater gift than that of giving one's time and energy to help others without expecting anything in return." We may never see the likes of Madiba again, but we can honor and emulate him by taking time today, and all other days, to engage in acts of service.