A presidential election to replace late Venezuelan leader Hugo Chavez will be held on 14 April, the country's electoral commission has said.
The announcement follows the appointment of Mr Chavez's favoured successor, Nicolas Maduro, as acting president.
Hugo Chavez died on 5 March after a long battle with cancer.
Mr Maduro will run as the governing party candidate with Henrique Capriles expected to stand for the opposition.
Mr Chavez - who led Venezuela for 14 years - won last October's election against Mr Capriles, polling 54% of the vote to Mr Capriles's 44%.
As Mr Chavez's health worsened, he announced that his vice-president, Mr Maduro, should succeed him.
Mr Maduro, 50, has pledged to carry on the former president's leftist policies and opinion polls have shown him as the favourite to win the next election.
The head of the electoral commission, Tibisay Lucena, said the candidates would have to register for the race by Monday.
Shortly after his announcement, the head of the opposition coalition officially proposed Mr Capriles, 40, as their presidential candidate.
Mr Capriles tweeted that he was grateful to be chosen, adding that he was analysing the statement from the electoral commission.
"In the following hours I will give my decision," he said.
Mr Capriles - a lawyer by training - is governor of the state of Miranda.
He describes his policies as "centrist" and "humanist" and says his political inspiration is former Brazilian President Luiz Inacio Lula da Silva who courted businesses and investors while also developing social programmes.
Despite the outpouring of grief and affection for Hugo Chavez, whose lavish state funeral was held on Friday, the opposition believe they have a chance of winning the election, the BBC's Will Grant reports.
Millions of Venezuelans have filed past his coffin as it continues to lie in state in a military museum in Caracas.
Mr Maduro has announced that the former leader's body will be embalmed "like Lenin and Mao Zedong".
The opposition boycotted Mr Maduro's swearing-in on Friday, saying that it was unconstitutional.
It argued that - under the constitution - the speaker of the National Assembly, Diosdado Cabello, should be the one to take over as acting president.
Mr Capriles called the move fraudulent.
The opposition further argues that, according to the constitution, the election should be held within 30 days of Mr Chavez's death. The date picked falls outside that period.
Meanwhile, Acting President Mr Maduro held one of his first diplomatic appointments on Saturday when he had a private meeting with the Chinese delegation that attended Friday's state funeral.
He told the Chinese representatives that Beijing "can count with the Bolivarian government, with the people of Venezuela to deepen the strategic alliance that our two countries have".
He and Nicaraguan President Daniel Ortega later visited the military academy where Mr Chavez is lying in state.