After six weeks of intensive hospital treatment, Ndileka Mandela told AFP her grandfather was "steadily improving" and "using his eyes, nodding."
That message was echoed by President Jacob Zuma who visited his predecessor's Pretoria bedside "found him really stable and I was able to say 'happy birthday' and he was able to smile."
That is a dramatic turnaround for the ailing peace icon, who just weeks ago was thought to be close to death.
Mandela was rushed to hospital on June 8 with a recurring lung infection that had already put him in hospital three times in less than a year.
Outside the Pretoria facility which has been the focal point of a national vigil for the last 41 days, there were joyous scenes.
Revellers sang anti-apartheid struggle songs, school children read poems dedicated to a man nearing the end of his long walk that took him from political prisoner to South Africa's first black president.
"Tata (father) Mandela has once again proved that he is a fighter," said well-wisher Agnes Shilowane, a local university student.
Thursday's news was a relief elsewhere in the country to South Africans who marked Mandela Day with a panoply of good deeds.
Biker gangs cleaned streets, volunteers painted schools and politicians spent 67 minutes on worthy projects -- all to mark Mandela's 67 years of public service.
Near Pretoria, Zuma tried to channel Mandela's cross-community appeal by delivering government housing to poor whites.
Messages of support also poured in from around the world -- and even from astronauts on the International Space Station -- to mark the anniversary, which many eared Mandela would not live to see.
US President Barack Obama -- who was unable to visit Mandela during a trip to South Africa last month -- led tributes to the peace icon, calling on people to honour him through volunteer work.
"Our family was deeply moved by our visit to Madiba's former cell on Robben Island during our recent trip," Obama said in a statement.
"We will forever draw strength and inspiration from his extraordinary example of moral courage, kindness, and humility."
Other well-wishers included the Dalai Lama, former US president Bill Clinton and his wife Hillary, US actor Morgan Freeman and Mandela's former jailer FW de Klerk, who went on to share the Nobel Peace Prize with him.
"Mandela's place in South Africa's history is assured," former president De Klerk said in a statement.
"His legacy of courage, perseverance and magnanimity will continue to inspire us -- and people throughout the world -- for generations to come."
'Oxtail and dumplings'
The Mandela family also did their bit, with his grandchildren volunteering at a children's home.
They were then expected to gather at the hospital for lunch, along with Mandela's third wife Graca Machel, who also celebrates 15 years of marriage to her husband today.
"We're doing our 67 minutes and bringing our old clothes that we're not using anymore. Then we'll converge at the hospital to have lunch with granddad," said Mandela's granddaughter Ndileka said.
She said the birthday meal would include Mandela's favourite food, including "oxtail, prawns, dumplings and vegetables".
Another granddaughter, Zaziwe Dlamini-Manaway, distributed food at a school.
"I think it's important for us to give back," she said.
"We are a family, we hope for him to come home, and we know the whole nation would hope the same thing, and the whole world."
The United Nations declared the Nobel Peace laureate's birthday Mandela Day in 2010, but for many this year it takes on extra poignancy.
In central Lisbon the Don Pedro IV Square was to be renamed Nelson Mandela Square, and an open-air Mandela-themed opera concert was planned in Paris.
On Saturday, the Australian city of Melbourne will hold a concert featuring local and African artists.
Born on July 18, 1918, Mandela fought against white rule in South Africa as a young lawyer and was convicted of treason in 1964.
He spent the next 27 years in jail.
It was in part through his willingness to forgive his white jailers that Mandela made his indelible mark on history.
After negotiating an end to apartheid, he became South Africa's first black president, drawing a line under centuries of colonial and racist suppression.
He then led reconciliation in the deeply divided country.
But the sunset of Mandela's life has been somewhat eclipsed by bitter infighting among his relatives.
A row over his final resting place has seen three of his children's graves dug up and their remains moved amid public brawling and legal action among his children and grandchildren.
source: www.abs-cbnnews.com
