Tyrone E. Martin appeals the trial court’s ruling on his letter seeking mitigation of his sentence. The trial court treated the letter as a motion filed pursuant to Florida Rule of Criminal Procedure 3.800(c), and denied it as untimely. We treat this appeal as petition for writ of certiorari. See Knafel v. State, 714 So.2d 1195 (Fla. 2d DCA 1998); Brown v. State, 707 So.2d 1191 (Fla. 2d DCA 1998). Because Martin’s motion was filed well beyond the sixty-day period set forth in rule 3.800(c) and no manifest injustice has been demonstrated, we deny the petition.