Times change. A statute passed today may seem obsolete tomorrow. Does the Constitution dictate when a law effectively expires? In Shelby County v. Holder, the 2013 decision that invalidated a provision of the Voting Rights Act, the Court seems to answer that question in the affirmative. Although rational and constitutional when written, the Court held that the coverage formula of the law grew to be irrational over time and was unconstitutional now because it bears “no logical relation to the present day.” This reason for invalidating a law is puzzling. The question answered in Shelby County was not about whether Congress had constitutional power to pass the Voting Rights Act. It was not even about whether our understanding of the scope of that power had changed from 1965 to 2013. The question was whether the passage of time and changed circumstances created a distinct reason to nullify the law.In this Article, I label this question one of a “constitutional shelf life.” The plaintiffs in Shelby County were not the first ones to ask for invalidation of an unconstitutionally stale law, and they will not be the last. Indeed, since the decision, plaintiffs as varied as marijuana enthusiasts and funeral-home directors have cited Shelby County for the claim that the “current burdens” of a law “must be justified by current needs.” The goal of this Article is to track the idea of a shelf life across various aspects of constitutional law, to demonstrate that the issue arises in far more contexts than one might anticipate, and then to offer an approach for principled application.