McFarland was sentenced in 2018 to six years in prison for several cases of fraud, and must now leave the prison prematurely.
He will now spend the summer in an exclusion unit before being released at the end of August.
Fyre Festival was arranged in 2017 by McFarland together with rapper Ja Rule.
It was sold as an exclusive luxury festival on a paradise island, with world artists and accommodation and top-class food.
A VIP ticket went for the equivalent of SEK 100,000.
But the well-to-do visitors were greeted by something resembling a windswept tent camp after a natural disaster, with neither food nor music.
Several visitors appealed to the US Embassy for help and the fiasco spread quickly on social media.
When McFarland was convicted, he had debts of almost SEK 300 million to festival visitors, staff and sponsors.