In Day v. McDonough, 547 U.S. 198 (2006), the Court was confronted with a mathematical miscalculation where the state said in its answer that the habeas petition was timely when it was actually untimely by three weeks. 547 U.S. at 201-02. The district court sua sponte dismissed the petition as untimely and the Eleventh Circuit affirmed. Id. at 202. The Supreme Court stated that although it would be an abuse of discretion to override a States deliberate waiver of a limitations defense, there was not an intelligent waiver on the States part, only an evident miscalculation of the elapsed time under a statute designed to impose a tight time constraint on federal habeas petitioners. Id. The Supreme Court held that a district court has the discretion, but not the obligation, to consider on its own motion the timeliness of a habeas petition under Antiterrorism and Effective Death Penalty Act (AEDPA) if: (1) the parties have fair notice and an opportunity to be heard; (2) the state has not waived the limitations defense; (3) the "petitioner is not significantly prejudiced by the delayed focus on the limitation issue"; (4) the court "determines whether the interests of justice would be better served by addressing the merits or by dismissing the petition as time barred." 547 U.S. at 209-11, 126 S.Ct. 1675. The Court affirmed a federal district courts authority to consider a forfeited habeas defense when extraordinary circumstances so warrant. 547 U.S., at 201. The State in Day, having miscalculated a time span, erroneously informed the District Court that Days habeas petition was timely. Apprised of the error by a Magistrate Judge, the District Court, sua sponte, dismissed the petition as untimely. The Court affirmed, holding that district courts are permitted, but not obliged, to consider, sua sponte, the timeliness of a state prisoners habeas petition. Id., at 209. Such leeway was appropriate, the Court again reasoned, because AEDPAs (Antiterrorism and Effective Death Penalty Act) statute of limitations, like the exhaustion doctrine, implicates values beyond the concerns of the parties. Id., at 205. It would be an abuse of discretion for a court to override a States deliberate waiver of a limitations defense. Day, 547 U.S., at 202.