William H. Harwood, federal prisoner # 03271-063, is serving, inter alia, a 20-year sentence for the use and carrying of a firearm during the commission of a drug-trafficking offense. Harwood has appealed the district court’s dismissal of his 28 U.S.C. § 2241 petition challenging the method used by the Bureau of Prisons (BOP) to compute the good-time credit against his sentence authorized by 18 U.S.C. § 3624(b). Harwood contends that the BOP formula reduces his sentence by only 46 days of good-time credit for each year served rather than the 54 days of credit specified by § 3624(b).

Regardless whether Harwood’s sentence is computed on the basis of the BOP’s interpretation of § 3624(b) or his own, Harwood’s release is not imminent. In light of the “temporally distant and speculative nature of [Harwood’s] claim,” he has failed to establish an “immediate injury” that would be redressed by the relief that he seeks. See Sample v. Morrison, 406 F.3d 310, 312 (5th Cir. 2005). Accordingly, we conclude that Harwood’s § 2241 petition is not ripe for review, and we dismiss *305 the appeal for lack of subject matter jurisdiction.

APPEAL DISMISSED.