It also proposed that campaigning run from May 17 to June 26.
The interim government was established with the help of international mediators in the wake of an assassination attempt on Captain Moussa Dadis Camara, the then-leader of the country's military government.
Camara, who was shot in the head by an aide, is recuperating in neighbouring Burkina Faso.
Ahead of the assassination attempt Guinea had been thrown into political turmoil when a security force crackdown on September 28 saw the massacre of 156 protesters.
A United Nations report released in December blamed Camara for the massacre.
The killings occurred as opposition supporters staged a rally amid concerns that Camara - who seized power in 2008 after the death of Lansana Conte, Guinea's long-time ruler - was planning to renege on a pledge to hold civilian elections.
Besides scores who died after soldiers opened fire in the city's main sports stadium, more than 100 women were reportedly raped during the incident.