There is no simple answer to this question as there is so much to see and do in South Africa. If you want to get a taste of the country, you could spend a week in Cape Town and its surrounds, visiting Table Mountain, Kirstenbosch Botanical Gardens, Robben Island, and the Winelands. For a wildlife experience, you could spend a few days in Kruger National Park. And if you want to explore more of the country, you could take a road trip along the Garden Route or through the Karoo Desert. So how many days you need really depends on what kind of trip you want to have.