The military junta has promised not to stand in the elections
Niger's military rulers have promised to revert to civilian rule before the anniversary of their 18 February coup, ousting ex-President Mamadou Tandja.
A referendum on a new constitution will be held in October, with the vote for president taking place by 26 December, a junta spokesperson said.
If there is no clear winner, a second vote will be held in January 2011.
The military will not be allowed to stand in the forthcoming elections, the BBC's Idy Baraou in Niger says.
After the coup, the largely arid but uranium-rich country was expelled from the African Union and the international community urged the junta to hold elections as soon as possible.
Mr Tandja, a former army officer, was first elected in 1999 and was returned to power in an election in 2004.
He came under increasing criticism both at home and abroad after changing the constitution to allow him to stay in power for a third term.
On taking power, the junta - headed by Maj Salou Djibo - promised to turn the country into an example of "democracy and good governance" and save its people from "poverty, deception and corruption".