Mandela, who turned 92, was spending the day with his family in Johannesburg. His wife went to an orphanage in Soweto to help plant a vegetable garden.
Graca Machel said today was a day for people to say: “I can extend my goodness to other people.”
Mandela Day, inaugurated last year and falling on the anti-apartheid leader’s birthday, was conceived as an international day devoted to public service.
National police commissioner Nathi Mthethwa said that spirit drew him to a Pretoria township where anti-foreigner violence broke out two years ago. He urged the community to be peaceful and unified.