PER CURIAM.
Appellant filed a motion seeking gain-time, along with a petition in support of his motion. When his motion was denied he moved for rehearing of his motion pursuant to Florida Rule of Criminal Procedure 3.800(a). We can assume from the motion for rehearing that the original motion was also filed pursuant to rule 3.800(a). We agree with the First District Court of Appeal's conclusion in Griffis v. State, 593 So.2d 308 (Fla. 1st DCA 1992), that a motion for rehearing does not postpone rendition of an order disposing of a rule 3.800(a) motion. Id. at 308.
In order for the notice of appeal in this case to have been timely as to the May 18, 1992, order of denial, it had to have been filed by June 17, 1992. The notice filed July 17, 1992 was therefore untimely, and as a result this court lacks jurisdiction of the cause. We sua sponte dismiss the appeal on the authority of Griffis v. State.
GLICKSTEIN, C.J., and DOWNEY and POLEN, JJ., concur.