opinion: Justice Ginsburg
  delivered the opinion of the Court.
  This case concerns the authority of a U. S. District Court, on its own initiative, to dismiss as untimely a state prisoner’s petition for a writ of habeas corpus. The Antiterrorism and Effective Death Penalty Act of 1996 (AEDPA), 110 Stat. 1214, sets a one-year limitation period for filing such petitions, running from “the date on which the judgment became final by the conclusion of direct review or the expiration of the time for seeking such review.” 28 U. S. C. § 2244(d)(1)(A). The one-year clock is stopped, however, during the time the petitioner’s “properly filed” application for state postconviction, relief “is pending.” §2244(d)(2). Under Eleventh Circuit precedent, that tolling period does not include the 90 days in which a petitioner might have sought certiorari review in this Court challenging state-court denial of postconviction relief. Coates v. Byrd, 211 F. 3d 1225, 1227 (2000).
  In the case before us, the State’s answer to the federal habeas petition “agree[d] the petition [was] timely” because it was “filed after 352 days of untolled time.” App. 24. Inspecting the pleadings and attachments, a Federal Magistrate Judge determined that the State had miscalculated the tolling time. Under Circuit precedent, the untolled time was 388 days, rendering the petition untimely by some three weeks. After affording the petitioner an opportunity to show cause why the petition should not be dismissed for failure to meet the statutory deadline, and finding petitioner’s responses inadequate, the Magistrate Judge recommended dismissal of the petition. The District Court adopted the Magistrate Judge’s recommendation, and the Court of Appeals affirmed, concluding that “[a] concession of timeliness by the state that is patently erroneous does not compromise the authority of a district court sua sponte to dismiss a habeas petition as untimely, under AEDPA.” Day v. Crosby, 391 F. 3d 1192, 1195 (CA11 2004) (per curiam).
  The question presented is whether a federal court lacks authority, on its own initiative, to dismiss a habeas petition as untimely, once the State has answered the petition without contesting its timeliness. Ordinarily in civil litigation, a statutory time limitation is forfeited if not raised in a defendant’s answer or in an amendment thereto. Fed. Rules Civ. Proc. 8(c), 12(b), and 15(a). And we would count it an abuse of discretion to override a State’s deliberate waiver of a limitations defense. In this case, however, the federal court confronted no intelligent waiver on the State’s part, only an evident miscalculation of the elapsed time under a statute designed to impose a tight time constraint on federal habeas petitioners. In the circumstances here presented, we hold, the federal court had discretion to correct the State’s error and, accordingly, to dismiss the petition as untimely under AEDPA’s one-year limitation.
  I
  Petitioner Patrick A. Day was convicted of second-degree murder and sentenced to 55 years in prison by a Florida trial court. Day unsuccessfully appealed the sentence, which was affirmed on December 21, 1999. Day did not seek this Court’s review of the final state-court decision; his time to do so expired on March 20, 2000.
  Three hundred and fifty-three (353) days later, Day unsuccessfully sought state postconvietion relief. The Florida trial court’s judgment denying relief was affirmed on appeal, and the appellate court issued its mandate on December 3, 2002. See Nyland v. Moore, 216 F. 3d 1264, 1267 (CA11 2000) (under Florida law, appellate order “is pending” until the mandate issues). Thirty-six (36) days thereafter, on January 8, 2003, Day petitioned for federal habeas relief asserting several claims of ineffective assistance of trial counsel. A Magistrate Judge, finding the petition “in proper form,” App. 21, ordered the State to file an answer, id., at 21-22. In its responsive pleading, the State failed to raise AEDPA’s one-year limitation as a defense. See supra, at 201. Overlooking controlling Eleventh Circuit precedent, see Coates, 211 F. 3d, at 1227, the State calculated that the petition had been “filed after 352 days of untolled time,” and was therefore “timely.” App. 24. The State’s answer and attachments, however, revealed that, had the State followed the Eleventh Circuit’s instruction on computation of elapsed time, the timeliness concession would not have been made: Under the Circuit’s precedent, more than one year, specifically, 388 days of untolled time, had passed between the finality of Day’s state-court conviction and the filing of his federal habeas petition.
  A newly assigned Magistrate Judge noticed the State’s computation error and ordered Day to show cause why his federal habeas petition should not be dismissed as untimely. Id., at 26-30. Determining that Day’s responses did not overcome the time bar, the Magistrate Judge recommended dismissal of the petition, App. to Pet. for Cert. 8a-15a, and the District Court adopted that recommendation, id., at 7a.
  The Eleventh Circuit granted Day a certificate of appeal-ability on the question “[wjhether the district court erred in addressing the timeliness of [Day’s] habeas corpus petition . . . after the [State] had conceded that [the] petition was timely.” App. 37. In a decision rendered two years earlier, Jackson v. Secretary for Dept. of Corrections, 292 F. 3d 1347 (2002), the Eleventh Circuit had ruled that, “even though the statute of limitations is an affirmative defense, the district court may review sua sponte the timeliness of [a federal habeas] petition.” Id., at 1349. Adhering to Jackson, and satisfied that the State’s concession of timeliness “was patently erroneous,” the Eleventh Circuit affirmed the dismissal of Day’s petition. 391 F. 3d, at 1192-1195.
  We granted certiorari sub nom. Day v. Crosby, 545 U. S. 1164 (2005), in view of the division among the Circuits on the question whether a district court may dismiss a federal habeas petition as untimely under AEDPA, despite the State’s failure to raise the one-year limitation in its answer to the petition or its erroneous concession of the timeliness issue. Compare, e. g., Long v. Wilson, 393 F. 3d 390, 401-404 (CA3 2004), and 391 F. 3d, at 1194-1195 (case below), with Scott v. Collins, 286 F. 3d 923, 930-931 (CA6 2002), and Nardi v. Stewart, 354 F. 3d 1134, 1141-1142 (CA9 2004).
  II
  A statute of limitations defense, the State acknowledges, is not “jurisdictional,” hence courts are under no obligation to raise the time bar sua sponte. See, e. g., Acosta v. Artuz, 221 F. 3d 117, 122 (CA2 2000); Hill v. Braxton, 277 F. 3d 701, 705 (CA4 2002); Davis v. Johnson, 158 F. 3d 806, 810 (CA5 1998); cf. Kontrick v. Ryan, 540 U. S. 443, 458 (2004) (defendant forfeited untimeliness argument “by failing to raise the issue until after [the] complaint was adjudicated on the merits”). In this respect, the limitations defense resembles other threshold barriers — exhaustion of state remedies, procedural default, nonretroactivity — courts have typed “nonjurisdictional,” although recognizing that those defenses “implicate] values beyond the concerns of the parties.” Acosta, 221 F. 3d, at 123 (“The AEDPA statute of limitation promotes judicial efficiency and conservation of judicial resources, safeguards the accuracy of state court judgments by requiring resolution of constitutional questions while the record is fresh, and lends finality to state court judgments within a reasonable time.”).
  On the exhaustion of state remedies doctrine, requiring state prisoners, before invoking federal habeas jurisdiction, to pursue remedies available in state court, Granberry v. Greer, 481 U. S. 129 (1987), is the pathmarking case. We held in Granberry that federal appellate courts have discretion to consider the issue of exhaustion despite the State’s failure to interpose the defense at the district-court level. Id., at 133. Later, in Caspari v. Bohlen, 510 U. S. 383, 389 (1994), we similarly held that “a federal court may, but need not, decline to apply [the nonretroactivity rule announced in Teague v. Lane, 489 U. S. 288, 310 (1989) (plurality opinion),] if the State does not argüe it.” See also Schiro v. Farley, 510 U. S. 222, 229 (1994) (declining to address nonretroactivity defense that State raised only in Supreme Court merits brief, “[although we undoubtedly have the discretion to reach” the argument).
  While the issue remains open in this Court, see Trest v. Cain, 522 U. S. 87, 90 (1997), the Courts of Appeals have unanimously held that, in appropriate circumstances, courts, on their own initiative, may raise a petitioner’s procedural default, i. e., a petitioner’s failure properly to present an alleged constitutional error in state court, and the consequent adequacy and independence of state-law grounds for the state-court judgment. See Brewer v. Marshall, 119 F. 3d 993, 999 (CA1 1997); Rosario v. United States, 164 F. 3d 729, 732 (CA2 1998); Sweger v. Chesney, 294 F. 3d 506, 520 (CA3 2002); Yeatts v. Angelone, 166 F. 3d 255, 261 (CA4 1999); Magouirk v. Phillips, 144 F. 3d 348, 358 (CA5 1998); Sowell v. Bradshaw, 372 F. 3d 821, 830 (CA6 2004); Kurzawa v. Jordan, 146 F. 3d 435, 440 (CA7 1998); King v. Kemna, 266 F. 3d 816, 822 (CA8 2001) (en banc); Vang v. Nevada, 329 F. 3d 1069, 1073 (CA9 2003); United States v. Wiseman, 297 F. 3d 975, 979 (CA10 2002); Moon v. Head, 285 F. 3d 1301, 1315, n. 17 (CA11 2002).
  Petitioner Day relies heavily on Rule 4 of the Rules Governing Section 2254 Cases in the United States District Courts (Habeas Rules), i. e., the procedural Rules governing federal habeas petitions from state prisoners, in urging that AEDPA’s limitation may be raised by a federal court sua sponte only at the preanswer, initial screening stage. Habeas Rule 4 provides that district courts “must promptly examine”, state prisoner habeas petitions and must dismiss the petition “[i]f it plainly appears . . . that the petitioner is not entitled to relief.” Once an answer has been ordered and filed, Day maintains, the court loses authority to rule the petition untimely sua sponte. At that point, according to Day, the Federal Rules of Civil Procedure hold sway. See Habeas Rule 11 (“The Federal Rules of Civil Procedure, to the extent that they are not inconsistent with any statutory provisions or these rules, may be applied to a proceeding under these rules.”). Under the Civil Procedure Rules, a defendant forfeits a statute of limitations defense, see Fed. Rule Civ. Proc. 8(c), not asserted in its answer, see Rule 12(b), or an amendment thereto, see Rule 15(a).
  The State, on the other hand, points out that the statute of limitations is akin to other affirmative defenses to habeas petitions, notably, exhaustion of state remedies, procedural default, and nonretroactivity. Indeed, the statute of limitations is explicitly aligned with those other defenses under the current version of Habeas Rule 5(b), which provides that the State’s answer to a habeas petition “must state whether any claim in the petition is barred by a failure to exhaust state remedies, a procedural bar, non-retroactivity, or a statute of limitations.” The considerations of comity, finality, and the expeditious handling of habeas proceedings that motivated AEDPA, the State maintains, counsel against an excessively rigid or formal approach to the affirmative defenses now listed in Habeas Rule 5. Citing Granberry, 481 U. S., at 131-134, as the instructive case, the State urges express recognition of an “intermediate approach.” Brief for Respondent 14 (internal quotation marks omitted); see also id., at 25. In lieu of an inflexible rule requiring dismissal whenever AEDPA’s one-year clock has run, or, at the opposite extreme, a rule treating the State’s failure initially to plead the one-year bar as an absolute waiver, the State reads the statutes, Rules, and decisions in point to permit the “exercise [of] discretion in each case to decide whether the administration of justice is better served by dismissing the case on statute of limitations grounds or by reaching the merits of the petition.” Id., at 14. Employing that “intermediate approach” in this particular case, the State argues, the petition should not be deemed timely simply because a government attorney calculated the days in between petitions incorrectly.
  We agree, noting particularly that the Magistrate Judge, instead of acting sua sponte, might have informed the State of its obvious computation error and entertained an amendment to the State’s answer. See Fed. Rule Civ. Proc. 15(a) (leave to amend “shall be freely given when justice so requires”); see also 28 U. S. C. § 2243 (State’s response to habeas petition may be amended by leave of court); cf. Long, 393 F. 3d, at 402-404 (District Court raised the statute of limitations sua sponte, the State agreed with that disposition, and the Court of Appeals treated that agreement as a constructive amendment to the State’s answer). Recognizing that an amendment to the State’s answer might have obviated this controversy, we see no dispositive difference between that route, and the one taken here. See Brief for Respondent 24 (“Here, the State did not respond to the show cause order because its concession of timeliness was based on an erroneous calculation and it agreed the petition should be dismissed as untimely.”); cf. Slack v. McDaniel, 529 U. S. 473, 487 (2000) (admonishing against interpretation of procedural prescriptions in federal habeas cases to “trap the unwary pro se prisoner” (quoting Rose v. Lundy, 455 U. S. 509, 520 (1982))).
  In sum, we hold that district courts are permitted, but not obliged, to consider, sua sponte, the timeliness of a state prisoner’s habeas petition. We so hold, noting that it would make scant sense to distinguish in this regard AEDPA’s time bar from other threshold constraints on federal habeas petitioners. See supra, at 206-207; Habeas Rule 5(b) (placing “a statute of limitations” defense on a par with “failure to exhaust state remedies, a procedural bar, [and] nonretroactivity”); Long, 393 F. 3d, at 404 (“AEDPA’s statute of limitations advances the same concerns as those advanced by the doctrines of exhaustion and procedural default, and must be treated the same.”). We stress that a district court is not required to doublecheck the State’s math. If, as this Court has held, “[district judges have no obligation to act as counsel or paralegal to pro se litigants,” Pliler v. Ford, 542 U. S. 225, 231 (2004), then, by the same token, they surely have no obligation to assist attorneys representing the State. Nevertheless, if a judge does detect a clear computation error, no Rule, statute, or constitutional provision commands the judge to suppress that knowledge. Cf. Fed. Rule Civ. Proc. 60(a) (clerical errors in the record “arising from oversight or omission may be corrected by the court at any time of its own initiative or on the motion of any party”).
  Of course, before acting on its own initiative, a court must accord the parties fair notice and an opportunity to present their positions. See, e.g., Acosta, 221 F. 3d, at 124-125; McMillan v. Jarvis, 332 F. 3d 244, 250 (CA4 2003). Further, the court must assure itself that the petitioner is not significantly prejudiced by the delayed focus on the limitation issue, and “determine whether the interests of justice would be better served” by addressing the merits or by dismissing the petition as time barred. See Granberry, 481 U. S., at 136. Here, the Magistrate Judge gave Day due notice and a fair opportunity to show why the limitation period should not yield dismissal of the petition. The notice , issued some nine months after the State answered the petition. No court proceedings or action occurred in the interim, and nothing in the record suggests that the State “strategically” withheld the defense or chose to relinquish it. From all that appears in the record, there was merely an inadvertent error, a miscalculation that was plain under Circuit precedent, and no abuse of discretion in following this Court’s lead in Granberry and Caspari, described supra, at 206-207.
  * H=
  For the reasons stated, the judgment of the Court of Appeals is
  Affirmed.
  Until AEDPA took effect in 1996, no statute of limitations applied to habeas petitions. See Mayle v. Felix, 545 U. S. 644, 654 (2005). Courts invoked the doctrine of “prejudicial delay” to screen out unreasonably late filings. See generally 2 R. Hertz & J. Liebman, Federal Habeas Corpus Practice and Procedure §24 (4th ed. 2001). In AEDPA, Congress prescribed a uniform rule: “A 1-year period of limitation shall apply to an application for a writ of habeas corpus by a person in custody pursuant to the judgment of a State court.” 28 U. S. C. § 2244(d)(1).
  Day urges this Court to find his petition timely. He asserts that the Eleventh Circuit misinterpreted § 2244(d)(2) in holding that AEDPA’s time limitation was not tolled during the 90-day period he could have petitioned this Court to review the denial of his motion for state postconviction relief. See Brief for Petitioner 45-50. This question was not “set out in the petition [for certiorari], or fairly included therein,” and we therefore do not consider it here. This Court’s Rule 14.1(a). We note, however, that the Court recently granted certiorari in Lawrence v. Florida, No. 05-8820, post, p. 1039 (cert. granted, Mar. 27, 2006), which presents the question whether AEDPA’s time limitation is tolled during the pendency of a petition for certiorari from a judgment denying state postconviction relief. The instant opinion, we emphasize, addresses only the authority of the District Court to raise AEDPA’s time bar, not the correctness of its decision that the limitation period had run.
  Day reads the Eleventh Circuit’s opinion in this case as rendering mandatory a district court’s sua sponte application of AEDPA’s one-year limitation, even when the respondent elects to waive the limitation and oppose the petition solely on the merits. See Tr. of Oral Arg. 6-8. He points to a sentence in the Eleventh Circuit’s brief per curiam opinion stating: “A federal court that sits in collateral review of a criminal judgment of a state court has an obligation to enforce the federal statute of limitations.” 391 F. 3d, at 1194. We read the Eleventh Circuit’s summary disposition in line with that court’s description of its controlling precedent: “We . . . ruled that, ‘even though the statute of limitations is an affirmative defense, the district court may review sua sponte the timeliness of [a federal habeas] petition.’ ” Ibid. (referring to Jackson v. Secretary for Dept. of Corrections, 292 F. 3d, at 1349; emphasis added); see also 391 F. 3d, at 1195 (State’s “patently erroneous” concession of timeliness “does not compromise the authority of a district court sua sponte to dismiss a habeas petition as untimely” under AEDPA’s one-year limitation (emphasis added)).
  In AEDPA, enacted nearly a decade after Granberry, Congress expressly provided that “[a] State shall not be deemed to have waived the exhaustion requirement or be estopped from reliance upon the requirement unless the State, through counsel, expressly waives the requirement.” 28 U. S. C. § 2254(b)(3).
  Trest held that a Court of Appeals was not obliged to raise procedural default on its own initiative, but declined to decide whether courts have discretion to do so. 522 U. S., at 89.
  Were we to accept Day’s position, courts would never (or, at least, hardly ever) be positioned to raise AEDPA’s time bar sua sponte. As this Court recognized in Pliler v. Ford, 542 U. S. 225, 282 (2004), information essential to the time calculation is often absent — as it was in this case — until the State has filed, along with its answer, copies of documents from the state-court proceedings.
  The Habeas Rules were amended after the proceedings below. We cite the current version because both parties agree that the amendments to Rules 4 and 11, effective December 1, 2004, wrought no relevant substantive change.
  See Rhines v. Weber, 544 U.S. 269, 276 (2005) (AEDPA’s time bar “quite plainly serves the well-recognized interest in the finality of state court judgments”; it “reduces the potential for delay on the road to finality.” (quoting Duncan v. Walker, 533 U. S. 167, 179 (2001))).
  The Court is unanimous on this point. See post, at 216, n. 2 (Scalia, J., dissenting).
  The procedural hindrance in Pliler was the petitioner’s failure to exhaust state remedies. The Court in that case declined to rule on the propriety of the stay-and-abeyance procedure that would enable a habeas petitioner to remain in federal court while exhausting unexhausted claims in state court. 542 U. S., at 231. In a later decision, Rhines, 544 U. S., at 278-279, this Court held that a district court has discretion to stay a mixed petition (i. e., one that includes both exhausted and unexhausted claims) to allow a habeas petitioner to present his unexhausted claims to the state court in the first instance, then return to federal court for review of his perfected petition.
  A district court’s discretion is confined within these limits. As earlier noted, should a State intelligently choose to waive a statute of limitations defense, a district court would not be at liberty to disregard that choice. See supra, at 202. But see post, at 217-218 (Scalia, J., dissenting).
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