Pakistan will also get three months to rebut the Indian version in writing before the International Court of Justice headquartered in the Dutch city of The Hague gets down to holding hearings to decide the Jadhav case.
Islamabad's deadline is 13 December, Foreign Ministry Spokesperson Gopal Baglay said, dismissing attempts by Pakistan to give the timeline outlined by UN's top court a different spin.
Quoting Pakistan's Attorney General Ashtar Ausaf Ali, a media report in Islamabad had claimed New Delhi wanted to prolong Jadhav's case at the world court and had sought six months to make its submissions. But the court had rejected this contention and told New Delhi to present its arguments by 13 September.
Mr Baglay said the international court's president had met representatives from both sides on June 8. "We submitted to the court a request for early proceedings in the matter. After submissions from both sides in regard to the timeline, ICJ has directed India to submit its memorial by 13 September 2017," he said.
"The interpretation that India wanted a certain timeline is not correct," he said.
The court proceedings may begin in January 2018.
India had approached the international court against the death sentence in May, describing the charges against Jadhav as "concocted" and his trial as "farcical". India's case is grounded in Pakistan's refusal to give Indian officials consular access to the former naval officer who was kidnapped from Iran last year.
In a hearing of the case on May 18, a 10-member bench of the ICJ restrained Pakistan from executing Jadhav, a retired Indian Navy officer who had been awarded death sentence by a Pakistan army court for alleged "involvement in espionage and terrorist activities in Pakistan".