Mandela, who turned 92 years old on Sunday, was spending the day with his family in Johannesburg, while his wife went to an orphanage in Soweto to help plant a vegetable garden.
The UN has declared Mandela's birthday on July 18 as Nelson Mandela International Day, in support of an appeal by the revered statesman for his birthday to be used for good deeds.
"Today is an opportunity for millions of people around the world to look inside themselves and find those beautiful qualities as any human being has and say: 'I am able to make a difference to my neighbor, to someone underprivileged, I can extend my goodness to other people,'" Mandela's wife Graca Machel said.
Scores of South Africans devoted 67 minutes of their time to community service to mark the number years Mandela spent in politics.
Image: Nelson Mandela relaxes a few minutes before the start of his 92nd birthday celebrations at his home in Johannesburg on July 18, 2010.
Text: IANS / AP