The term for the current government ends April 22, Zuma said in a statement.
"We hold national general elections without fail every five years, which demonstrates the maturing of our democracy," Zuma said.
"These are historic elections as they take place during the 20th anniversary of our freedom from apartheid bondage," he said. "They provide an opportunity for us to further consolidate the democracy and freedom that we worked so hard to achieve, and for which esteemed South Africans such as former President Nelson Mandela sacrificed life's comforts for."
He said the final voter registration period is Saturday and Sunday.
Zuma also congratulated 18-year-old, first-time voters, who he said "will be deciding the future of their beautiful country.
"Our country is a much better place to live in now than before 1994, because of the participation and contribution of South Africans," Zuma said. "We must continue participating in building our country."