Petitioner, serving fifty-one weeks in the county jail as a condition of probation, seeks by petition for writ of mandamus to have this court order jail officials to give him statutory gain time under section 951.-21, Florida Statutes (1981). The statute does not apply to incarceration as a condition of probation, as it is not a “sentence.” Heatherington v. State, 388 So.2d 1354 (Fla. *11805th DCA 1980); Adams v. State, 387 So.2d 498 (Fla. 5th DCA 1980). The petition for mandamus is

DENIED.