President Jacob Zuma said that South Africa was truly blessed to have a compatriot like Nelson Mandela in its midst, as he wished the former President a happy birthday for Saturday.

"All South Africans and people all over the world - black and white, men and women, young and old are united in their admiration, love and respect for Madiba. It takes a special kind of a person to generate so much love and respect," said Zuma in his weekly letter on Friday.

He said former President Mandela deserved to be honoured through the 67 minutes of volunteerism campaign, suggested by the foundation that promotes his work, because his entire adult life was spent in service of South Africa and for humanity throughout the world.

"It is an honour for us to be able to demonstrate our appreciation to him, and through him, to all our stalwarts and veterans who sacrificed their lives so that we could be free."

He described Mandela as a selfless leader "who personifies human dignity and the limitless possibilities of all human beings".

Mandela demonstrated the power of African leadership and was a beacon of hope for Africa and the world.

Zuma ran through some of the campaigns Mandela had participated in as part of the struggle against apartheid, and his peacekeeping work in Burundi.

"He taught us that you achieve freedom and inner peace if you release hatred from your heart.

"Madiba continued, through his gift of caring, to respect even those who once vilified, oppressed, embarrassed and even tortured him for his noble thoughts of a society free of oppression, where people would live in peace and equality.

"He taught us that living for a good cause transcends the innermost rooted feelings of prejudice, hatred or revenge. Therefore how can we do things differently, other than take our country towards peace, reconciliation and prosperity?"

He continued: "If there is a story to be told of an icon that inspires the world, characterised by the humility, warm humanity and a will for prosperity; then Madiba's 91 year life story offers a story of life worth living."

Mandela Day comes in the month South Africa chose for moral regeneration, and Zuma said that for values of compassion for the elderly, loving one's neighbour like family, "we look no further than Madiba".

Zuma's contribution to community service on Saturday would be spent in Ivory Park in Ekurhuleni, east of Johannesburg.

"This will be a celebration to honour the more than three-million senior citizens of our country, who are often neglected and treated as expired and unimportant members of our community.

"We will be sending out a message that if Tata means so much to us at the age of 91, our senior citizens should equally be treated with respect, honour and dignity."

From Saturday onwards, nobody should pass those in less favourable circumstances in dire need without pausing to think what can be done to help.

"Nelson Mandela Day is an international call to action: Recognise the power within you to make a difference and to change the world around you for the better.

"Let us hold each other's hands and commit ourselves to work together to do more to make South Africa a great country, to build a better Africa and a just world!

"Happy Birthday Tata Madiba, ukhule njalo! Happy Nelson Mandela Day to all!"