Zodwa Kgamphe baked a cake for needy children so that they, too, could celebrate the 95th birthday of the man they call the father of their nation: Nelson Mandela. But like most South Africans, Kgamphe was also giving thanks for a life shaped by the anti-apartheid icon.

“If it wasn’t for him, I would not be owning my own bakery,” said Kgamphe, 58, as her older sister nodded in agreement. “He taught us to work hard for ourselves. He gave us strength. He stayed 27 years in prison. If he could do that, I felt I could open my own business.”

On Thursday, South Africans of all races celebrated Mandela’s 95th birthday, amid reports that his health was “steadily improving” as he lay in a hospital bed battling a lung infection. At the urging of South African leaders and the United Nations, which recognizes his birthday as Nelson Mandela International Day, many South Africans paid tribute to him by volunteering for 67 minutes to mark Mandela’s 67 years of public service

They donated food to charities, worked in orphanages, picked up trash, made sandwiches for the poor and baked cakes. President Jacob Zuma oversaw donations of houses that were given to impoverished white farmers in Pretoria. A group of young artists created an exhibition of 95 posters compiled from submissions from around the world to commemorate Mandela.

And retired Archbishop Desmond Tutu, a Nobel Peace Prize laureate like Mandela, as well as a famed leader of the anti-apartheid struggle, painted the walls of a school in a shantytown in Cape Town.

Interactive Timeline: A timeline of the key events in the life of Nelson Mandela.

Outside the Mediclinic Heart Hospital in Pretoria, where Mandela was taken in early June, throngs gathered outside the green gates, singing, dancing or blowing vuvuzelas, the long plastic horns that were ubiquitous during the soccer World Cup held in South Africa in 2010.

Mercy Mokgoane, 39, noted that under the nation’s apartheid-era segregation laws, she wouldn’t have been allowed to stand in front of the hospital. “Only our mothers were allowed into this area, because they were the maids of the white people. The way we live now is because of Madiba,” she said, referring to Mandela by his Xhosa clan name.

With television crews from across the world covering the celebrations, marching bands played “Happy Birthday” and the national anthem. Schoolchildren dressed in the green and yellow colors of the ruling African National Congress party sang tributes to Mandela as their proud parents and teachers watched. Vendors sold Mandela T-shirts and pins.

Others signed the hundreds of banners plastered on the wall of the hospital. “Your life remains our inspiration,” read one poster.

“We are all here as a nation to celebrate the great man’s birthday,” said Constance Felix, 65, who took a six-hour bus ride from Eastern Cape province. “We are not down and out because he is sick. It shows the nation still has hope for him.”

When she heard reports that Mandela was doing better, she added: “My spirit is lifted up and encouraged. We need him to stay with us longer.”

In a statement, Zuma said Mandela’s “doctors have confirmed that his health is steadily improving.” Zuma did not refer to Mandela’s condition as “critical but stable,” as the government has.

On the eve of his birthday, Mandela’s daughter Zindzi Mandela-Motlhajwa told the British broadcaster Sky TV that her father has made “dramatic progress” and was gaining “energy and strength.”

“I visited him yesterday, and he was watching television with headphones,” she said. “He gave us a huge smile and raised his hand.”

She added, “I should think he will be going home anytime soon.”

In Soweto, scores gathered outside Mandela’s home, now a museum. Many signed a large banner dedicated to Mandela. Many of the messages referred to him as Tata, which in Xhosa means “father.”

In the late afternoon, one young woman walked up to the banner and wrote:

“Happy Birthday Tata, We love you so much and thanks for everything you have done for us.”

She paused, looking at what she had written, then smiled and walked away.