A day in remand, in accordance with law, is equivalent to two days in jail.
Since Mirzaev was in detention since august 2011, his jail term is now over.
The defence lawyer said he would appeal the verdict.
The Zamoskvoretsky court found Mirzaev guilty of killing the student during a conflict at a night club in Moscow but qualified the accusation as a softer crime.
The court took into account several circumstances that Mirzaev tried to help Agafonov who fell on the road, turned himself in to the police, cooperated with the investigators and sent money to the student’s family.
Voice of Russia, Interfax