Petitioner seeks certiorari review of the lower court’s order denying his Petition for Writ of Mandamus. He complains that the Department of Corrections is applying the incorrect gain-time law to his sentence. Because of this court’s recent decision in Duer v. Moore, 765 So.2d 743 (Fla. 1st DCA 2000), we must agree. Accordingly, we GRANT the petition, QUASH the order below, and REMAND for further proceedings consistent with this court’s opinion in Duer.