South Africa celebrated Nelson Mandela's 95th birthday on Thursday as the freedom fighter spent his 41st day in the hospital following a recurring lung infection.
Reports on Mandela's current medical condition vary, but the South African government said doctors had confirmed that he was steadily improving.
South Africans are being urged to mark the former president and anti-apartheid leader's 67 years of public service with 67 minutes of charitable acts.
President Jacob Zuma said his health was "steadily improving".
"We are proud to call this international icon our own as South Africans and wish him good health," said Mr Zuma in a statement.
"We thank all our people for supporting Madiba throughout the hospitalisation with undying love and compassion," he said, referring to Mr Mandela by his clan name.
"It's an honorable day for us because it's our grandfather's birthday, so it's literally a call for the whole world to go for service and to do something special," granddaughter Zaziwe Dlamini Manaway said.
July 18 has become known as "Nelson Mandela International Day," since the United Nations proclaimed it in 2009.
Students work in a public park in Cape Town on Thursday in honor of Nelson Mandela's 67 years of public service. Events are also taking place internationally, with an image of a large Mandela painting by South African artist Paul Blomkamp featured in New York's Times Square.
"It's basically a call for action for the whole world to do something for 67 minutes, to be selfless to do something to better someone else's life someone else's cause."
The former president is respected across the world for his role in ending apartheid in South Africa. He went on to become the first black president in the country's first multi-racial elections in 1994.
