concurring.

It has been said that “any law student, after a month in law school, knows that the *406answer to the question ‘Define X,’ is: ‘For what purpose are we defining this term?’ ”1 In this case, we must define “take effect” for the purpose of deciding when our judgments become the law, not when they become final. One would think judgments from this Court would become the law immediately. Indeed, there is no foreboding in the term “Judgment Day” if nothing happens until “Mandate Day.”

I agree with the Court that our decisions can take effect whenever we say they do. For example, in the school finance cases we postponed the effective date of one judgment for seven months,2 another for six months,3 and another for more than a year4 — all long after the judgment was final and the mandate had issued. Similarly, in a handful of special cases the Legislature has provided that an appellate judgment takes effect before the mandate,5 with the mandate,6 and after the mandate.7

But except in such special cases, it would be a waste of time for courts to set each effective date individually. Circumstances may dictate when a special judgment should take effect, but for all other judgments we need a general rule. Accordingly, I join in the Court’s judgment and all parts of its opinion except those that leave the general rule up in the air. For several reasons, the obvious and logical general rule is that our decisions should take effect on the date of judgment.

I. What Matters Is The Judgment

First of all, we should start with the principle that cases are decided by judgments, not mandates. Judgments are rendered by the court,8 and a majority of the court must agree to them.9 Mandates, by contrast, are drafted and signed by the clerk;10 judges rarely even see them. As Justice Pope wrote for this Court 80 years ago in Burrell v. Cornelius: “Judges render judgment; clerks enter them on the minutes.”11 Our decisions should take effect when the justices act, not the clerk.

Second, the appellate rules recognize in many places that the operative act binding the parties is the judgment, not the mandate:

•when a party dies during an appeal, “the appellate court’s judgment will have the same force and effect as if *407rendered when all parties were living”; 12

•when public officials leave office, their successors “will be bound by the appellate court’s judgment ....”;13 and •when a party voluntarily appears on appeal, or learns of its outcome, that party “is bound by the opinion, judgment, or order....”14

Because the judgment is the operative act of a court, its date should be the operative date.

Third, our judgments should mean what they say. “The controlling intention of the court’s judgment is that expressed on the face of the judgment....”15 If our judgment says something can or can’t be done, then that ought to be the law — immediately.16 If a judgment orders children taken from or returned to their parents, that should not wait for the mandate. If a judgment declares a fee unconstitutional, collection ought to stop at once.17 If our judgments have no effect until the mandate issues, then they do not mean what they say.18

Fourth, our standard treatment of stay orders shows we intend judgments to take effect immediately. The clerk cannot lift a stay order; the court must do so, and our standard procedure has been to lift a stay when we issue our judgment.19 The same practice is used in the courts of appeals: stays are lifted when the judgment issues.20 If our judgments do not take effect immediately, then parties can do whatever they want in the purgatory between judgment and mandate.

Fifth, for several decades we have tried to simplify the rules of procedure by insist*408ing that judgments bear a date and that deadlines run from it. To quote Justice Pope in Burrell again:

Law professors should teach, writers of legal form books should so correct their books, lawyers should so draft documents, and judges should make certain that above the signature on each judgment or order there are the words: “Signed this _ day of_, 19 » 21

Today, an appellate decision takes effect on the date of judgment for many purposes, including: when plenary power expires in the court of appeals;22 when a judgment becomes dormant;23 when limitations runs for filing a bill of review;24 when indemnity and third-party claims accrue; 25 and when tolling ends on alter ego claims.26 Clarity and certainty are lost if the judgment date counts for these purposes, but does not count when deciding when the judgment takes effect.

Sixth, judgments take effect immediately for all who are not parties in the case. Usually our opinions apply both prospectively and retroactively,27 but sometimes we apply a decision prospectively only, in which case our standard practice has been to declare the law from the date of judgment, not the date of finality or the mandate.28 This appears to be the practice of our sister court too.29 It would be very odd for our decisions to take effect for third parties before they take effect for the parties involved in the case.

Seventh and finally, we expect lower courts to follow our decisions without receiving an explicit order to do so.30 In *409mandamus cases, we generally grant the writ conditionally because we expect lower courts to comply without receiving the writ. But how can we expect lower courts to comply with our opinions immediately if they have not yet takén effect?

II. What About the Opinion?

One could argue that our decisions should take effect on the date of opinion rather than the date of judgment. In cases remanded for proceedings consistent with our opinion, the lower courts must have the opinion to carry out the judgment.31 Of course in most cases the opinion and judgment issue together, so the effective date for both is the same.32 But in a few cases they are different, and in those cases the date of judgment is more important.

In a few emergencies, we have issued judgments or orders with opinions to follow.33 For example, in In re Doe we issued a judgment on March 10, 2000 and the opinions three months later.34 In such cases, we clearly intended the judgments to take effect immediately; there was no other reason to issue them before the opinions were ready. And we certainly did not intend those judgments to take effect only when the mandate issued much later. Opinions, motions for rehearing, and mandates can issue in due course, but judgments ought to take effect immediately.

It is true that in emergency cases we can order the mandate issued early and deny the parties the right to file a motion for rehearing.35 But prohibiting motions for rehearing can mean missing an opportunity to correct a mistake. The best way to make judgments effective immediately, while still allowing for mistakes, is to make the effective date the date of judgment.

III. What About the Mandate?

Justice Willett’s proposal that our decisions should take effect only when the mandate issues will not work for one primary reason: after many of our opinions there is no mandate. Mandates issue only after a judgment.36 No mandate issues when we deny a petition, even if we do so by written opinion. Nor do mandates issue in mandamus proceedings, which we decide by “orders” rather than “judgments.” 37 If a mandate is required before this Court’s decisions take effect, then many of them never have and never will.

*410But there’s more. From 1892 until 1978, Texas law prohibited clerks from issuing a mandate until court costs were paid.38 Thus, for example, the first rules of civil procedure in 1941 provided:

On the rendition of a final judgment or decree in the Supreme Court, the clerk of said court shall not issue and deliver the mandate of the court, nor certify the proceedings to the lower court, until all costs accruing in the case in the Supreme Court and the Court of Civil Appeals have been paid ... 39

If costs were not paid within 12 months, the case was simply dismissed and no mandate ever issued.40 These rules were replaced in 1978,41 but it is hard to say how many judgments before then were never followed by a mandate. So which of our opinions have never taken effect? And how would anyone know without looking through files perhaps 100 years old?

As we explained in Continental Casualty Co. v. Street in 1963, a mandate is a procedural device intended to keep courts from issuing conflicting orders:

The rules relating to the return of the mandate from the appellate to the trial court are ... primarily procedural in nature. They provide for an orderly dispatch of judicial business by adopting procedures under which both the appellate and trial courts may have knowledge of the status of pending litigation and thus prevent the issuance of conflicting orders by the courts of the trial and appellate levels.42

Mandates are thus a means of communication between courts; they were not even required to be sent to the parties until 2003.43

*411This is why the rules provide for enforcement of our decisions only after the mandate.44 Postponing enforcement of our decisions is not the same as postponing when they are effective; indeed an injunction or declaratory judgment cannot be enforced by contempt unless it becomes effective sometime earlier. Appellate courts do not entertain motions for turnover, garnishment, or contempt; those must be filed in the trial court. Absent supersedeas, this means the case can be proceeding in two courts at once. In such cases, the mandate is our notice to the trial court that it can start enforcing a new judgment or proceed with enforcement of the old one without stepping on our toes.

This is also why a judgment in an interlocutory appeal “takes effect when the mandate is issued.”45 Here again, an interlocutory appeal (unlike a final appeal) means the case is pending in two courts at once. As a result, there is a daily potential for conflicting orders. The standard solution is to abate action in one of the two courts, as we do in cases of dominant jurisdiction.46 Sometimes, a statute or stay from the appeals court keeps the trial court from issuing conflicting orders.47 But in other cases, it may be best for the trial court to proceed, with the appellate court’s orders taking effect only with the mandate. The reason our rules abate the effective date in interlocutory appeals until the mandate, but say nothing about abating the effective date for final appeals, is because the two .cases are not the same.

IV. What About Finality?

If finality is the goal, the mandate is not the answer. First of all, mandates issue 10 days after our judgment is final;48 any argument to postpone the effective date until finality does not justify postponing it 10 days more. Moreover, mandates can be recalled;49 so while judgments and opinions can change, mandates can too.

The problem is that it is hard to say when our decisions are final. The rules of procedure place no explicit limit on our plenary power, as they do for the courts of appeals.50 And as we have noted several times before, judgments become “final” for different purposes at different times.51 Thus, for the purpose of review by the United States Supreme Court, a judgment from this Court is “final” immediately, not *412when the mandate issues.52 For purposes of res judicata and collateral estoppel, a judgment is also “final” even if the appeal is not.53 Holding that our judgments do not take effect until they are “final” serves only to confuse when they actually take effect.

As a historical matter, our judgments almost never change on rehearing. In the last 10 fiscal years, this Court issued more than 1100 majority and per curiam opinions. On rehearing, we changed less than 50 of the opinions, and those almost always in minor respects that had no effect on the judgment. In only four cases did the prevailing party in the judgment change.54 Thus, the chance that an original judgment will differ from the final judgment is about 1 in 300. We should not let such long odds dictate the general rule about when our judgments take effect.

Finally, there are also constitutional considerations in deciding when our decisions take effect. The Texas Constitution grants the Legislature alone the power to suspend laws.55 That provision has never prevented the courts from suspending a law that is itself unconstitutional. But once we decide that a law is constitutional, keeping the law suspended during our administrative steps leading, to finality and a mandate is (to say the least) problematic.

* * *

When a mandate conflicts with a judgment or opinion, it is the mandate that must yield.56 The same should be true regarding when our decisions take effect. Perhaps “it ain’t over till it’s over,” but a judgment from the Supreme Court of Texas ought to mean “it’s over.” Accordingly, as a general rule I would hold that our decisions take effect when we issue a judgment.

concurring.

I agree with the Court that under Bar-shop1 the Edwards Aquifer Authority became effective on the date of our opinion in that case. The issue as briefed to us, however, and as addressed at length by the court of appeals, raised a more fundamental legal question: When does an appellate-court judgment become final and take effect? This vexing question will no doubt recur and, in my view, warrants the Court’s rulemaking attention. To some degree, the issue has a certain “angels dancing on the head of a pin” quality to it, interesting (to some) as a matter of logic and perplexing (to all) as a matter of practice. It is confounding, to be sure, but also consequential.

So I join in the Court’s judgment and, like JUSTICE BRISTER, most of its opinion. But as a general matter the bet*413ter default date is the mandate, the formal order declaring our review complete, our decision final, and our judgment enforceable. Yogi Berra was right: In law as in life, “It ain’t over ‘til it’s over.”2

[[Image here]]

An appellate court’s mandate is the official order declaring to the district court, the parties, and all other interested persons that the court has closed the book on its review and is once-and-forall finished. I can understand, therefore, why the court of appeals and Chemical Lime view the date of our mandate in Barshop as when the Authority and the Edwards Aquifer Authority Act became effective. Their position is hardly unreasonable. A decision from this Court, of course, is subject to a motion for rehearing, and can also be reconsidered on our own motion.3

The Authority says the date of the Bar-shop mandate is inappropriate because issuance of the mandate is merely the “ministerial act” of a court clerk.4 I disagree. The mandate under our rules is not a mere ministerial postscript or duplicative reminder. Our rules require appellate courts to prepare a mandate, without which an appellate-court judgment cannot be enforced.5

Several statutes also tie the finality of appellate-court decisions to issuance of the mandate.6 If the mandate served no *414meaningful purpose there would be no need to require one.

In addition, Texas Rule of Appellate Procedure 18.6 makes clear that appellate-court judgments in accelerated appeals, when time is of the essence, are not effective until the mandate issues. It would be peculiar to hold, as the Authority urges, that our judgment in an ordinary, unex-pedited appeal takes effect instantly when the rules make plain that our judgment in an accelerated appeal7 takes effect only “when the mandate is issued.”8

The parties make several arguments as to whether the trial court’s judgment was superseded while Barshop was on appeal, and whether the trial court was obliged to follow Barshop immediately upon its issuance. The Authority argues the State was exempt from the requirement of filing a supersedeas bond under Section 6.001 of the Civil Practice and Remedies Code, and therefore the trial court’s declaratory judgment was automatically suspended when the State perfected its appeal.9

The Authority also argues that the trial court’s injunction against enforcement of the Act dissolved immediately when we issued our decision in Barshop. The Authority cites Poole v. Giles, where we stated that an appellate “order dissolving a temporary injunction is effective immediately even though not final.”10 It further cites Texas Workers’ Compensation Commission v. Garcia, in which we observed that even though the trial court and court of appeals had declared the Workers’ Compensation Act unconstitutional, they had not issued injunctions, and the Workers’ Compensation Commission had “accordingly continued implementing the Act notwithstanding the judgments of the courts below.”11 In contrast, we stated in Barshop that “[bjecause of the district court’s injunction,” the Act “has yet to be implemented,” but we concluded by holding that the injunction “is dissolved.”12

The court of appeals distinguished the trial court’s injunction and its declaratory judgment, reasoning that even if, immediately after our Barshop decision, “the district court could not enforce its injunction with contempt power ... this does not mean that the supreme court’s judgment declaring the [Act] constitutional and reversing the district court’s contrary declaration also became effective at that time.”13 Chemical Lime, too, contends that the Barshop judgment had no effect on the trial court’s declaratory judgment until our mandate issued, and that “[distinctions between injunctive and declaratory relief are irrelevant for this purpose.”

Chemical Lime further takes issue with the Authority’s contention that the State’s notice of appeal in Barshop automatically superseded the trial court’s judgment, characterizing this position as inconsistent with the position the State took in Bar-shop. In Barshop we noted the State’s position that it was before the Court *415“seeking authorization to implement the Act,” and that we should construe the Act “to merely require that the declarations be filed with the Authority six months after the eventual effective date of the statute.” 14 Chemical Lime argues that even if ordinarily the State was not required to post a supersedeas bond, the trial court in Barshop purported in its judgment to exercise its discretion “to deny supersedeas of this Judgment.” Chemical Lime contends the State chose not to challenge the order denying supersedeas and should not now be heard to argue that its notice of appeal in Barshop automatically superseded the judgment in that case.15 Indeed, taking the Authority’s argument to its logical conclusion might mean the Act was effective when the State filed its notice of appeal in Barshop in 1995, and the six-month window for filing declarations of historical use expired before our opinion issued on June 28,1996.

As the Court notes, these arguments regarding supersedeas and other issues are not dispositive,16 and they obscure a key point. I do not believe the trial court or the parties would have acted in a manner inconsistent with our opinion in Bar-shop after it issued, regardless of whether, in some technical sense, the injunction immediately dissolved when we so stated in Barshop or the trial-court judgment was superseded at the time. I assuredly do not suggest parties may flout an appellate-court decision or judgment merely because the mandate has not yet issued.

Nevertheless, our Barshop decision was still not “final”17 when issued in one important sense: We were still free to reconsider it and hold the Act unconstitutional or otherwise correct or modify our opinion or judgment. This authority of the issuing court to modify its own opinion or judgment ordinarily extends until the mandate issues, regardless of whether the judgment awards monetary, injunctive, or declaratory relief.

Although in exceptional circumstances we can recall the mandate,18 the date of the mandate is ordinarily the appellate court’s formal and final order signaling it is finished with its review of the case and considers its decision final and its judgment enforceable.19 Indeed, by correspondence the clerk advised the trial court and *416parties in Barshop as follows when the mandate issued: “The judgment of the Supreme Court of Texas is now final in the above referenced cause. As Rule 186, Tex. R.App. P., has been satisfied, we have issued the mandate as of today.” As the court of appeals aptly noted, the period between judgment and mandate affords the court “the opportunity to correct an appellate judgment before commanding its execution and enforcement in the lower court.”20 An appellate court can issue a mandate earlier than the rules ordinarily prescribe if it has good cause for making its judgment more immediately final and enforceable.21 Moreover, this Court has discretion to shorten the time for filing a motion for rehearing or even to disallow such a motion altogether.22 Again, if opinions were immediately final for all purposes upon issuance, there would be no need for a mandate and no reason for courts sometimes to issue mandates early or to shorten the usual timetable for rehearing motions.

The date of the mandate, therefore, is generally the date the parties’ duties become fixed.23 In this case, it was the date that all uncertainties regarding the Act’s constitutionality were finally and definitively dispelled.

Justice BristeR points out many peculiarities in the law (complicated, it seems, by our inconsistent adherence to myriad rules and internal practices).24 As between the opinion and the judgment, I *417agree with JUSTICE BRISTER that the judgment is more “operative” — the judgment takes action; the opinion explains why. I also agree that “judgments should mean what they say,” but the question remains: Which judgment?25 An appellate court can reconsider its judgment and the opinion on which it rests until the mandate issues, the date finality attaches.26

I appreciate Justioe Bkister’s point that the judgment merits instant respect. But if a judgment is operative for all purposes upon issuance, what exactly is the mandate of a mandate — why enact rules and statutes that tie finality and enforceability to something that amounts to Seinfeld-ian *418nothingness?27 It seems odd that a decision would be fully effective yet neither final nor enforceable.28

I agree with the Court that our decision in Barshop itself decides today’s case. I agree, too, with Justice BRIster that our decisions “can take effect whenever we say they do,”29 but as a general default rule, I would treat the mandate as a more-than-clerical act. It is the judicial equivalent of ‘Tes, that’s my final answer” — the disposi-tive order concluding the appeal, declaring the judgment final and enforceable, and commanding that the judgment be “recognized, obeyed, and executed.” I trust the Court’s rulemaking process will focus its expertise on this important issue and deliver bright-line guidance going forward.

delivered the opinion of the Court,

Whether, as a general matter, an appellate court’s decision takes effect the moment the court issues its opinion, order, or judgment, or later when rehearing is denied or the time for rehearing expires, or still later when the clerk issues the mandate, is a difficult question under Texas law and procedure, as reflected by the competing arguments in Justice BRisteR’s and Justice Willett’s separate opinions, and one we need not answer today. We all agree that if an appellate court expressly states the time for its decision to take effect, that statement controls. That rule applies here.

In Barshop v. Medina County Underground Water Conservation District, we prescribed a filing deadline “six months after the [Edwards Aquifer] Authority becomes effective”.1 As it happened, the Authority began operations the day we issued our opinion and thus became effective. The deadline was set at six months *394from that date. We hold that the Authority correctly applied Barshop, and therefore we reverse the judgment of the court of appeals.2 We remand the case to the trial court for further proceedings.

I

The Edwards Aquifer is an underground layer of porous, water-bearing rock, 300-700 feet thick, and five to forty miles wide at the surface, that stretches in an arced curve from Brackettville, 120 miles west of San Antonio, to Austin. It is the primary source of water for south central Texas and therefore vital to the residents, industry, and ecology of the region, the State’s economy, and the public welfare.

Record droughts in the early 1950s prompted the Legislature to create the Edwards Underground Water District in 19593 “for the purpose of conserving, protecting and recharging the [aquifer’s] underground water-bearing formations ... and for the prevention of waste and pollution”.4 Although the District’s powers were broadened over the years, it still lacked the regulatory authority the Legislature came to believe was essential. In 1993, the Legislature passed the Edwards Aquifer Authority Act (EAAA),5 which replaced the District with the Edwards Aquifer Authority, giving the Authority broad powers “for the effective control of the resource to protect terrestrial and aquatic life, domestic and municipal water supplies, the operation of existing industries, and the economic development of the state.”6 The EAAA also expanded the covered territory.

The EAAA prohibits withdrawals of water from the aquifer without a permit issued by the Authority,7 limits the total *395permitted withdrawals per calendar year,8 and gives preference to “existing user[s]” — defined as persons who “withdr[ew] and beneficially used underground water from the aquifer on or before June 1, 1993.”9 With few exceptions, water may not be withdrawn from the aquifer through wells drilled after June 1, 1993.10 A permit applicant must file with the Authority on a prescribed form11 a “declaration of historical use of underground water withdrawn from the aquifer during the historical period from June 1, 1972, through May 31,1993.”12 Subject to the limit on total withdrawals of water from the aquifer, an existing user who files a declaration “as required”, pays an application fee (set at $25), and “establishes by convincing evidence beneficial use of underground water from the aquifer”13 is entitled to “a permit for withdrawal of an amount of water equal to the user’s maximum beneficial use of water without waste during any one calendar year of the historical period.”14 After existing users’ applications have been processed, the Authority may issue additional permits up to the cap on total annual withdrawals.15 The Au*396thority’s board of directors is required to “adopt rules necessary to carry out the authority’s powers and duties ..., including rules governing procedures of the board and authority.” 16

The EAAA was enacted May 30, 1993. The Authority was to commence operations September 1,1993, the general effective date of the statute, but the new regulatory scheme was to be phased in over six months.17 Existing users had until March 1, 1994, to file permit applications,18 at which point the permit requirement would take effect. After March 1, a filer could generally continue to withdraw water pending approval of its application.19

But implementation of the EAAA was delayed. Prior to September .1, 1993, the United States Department of Justice refused administrative preclearance for the new Authority under section 5 of the Voting Rights Act of 1965.20 On May 29, 1995, the Legislature amended the EAAA to meet the Department’s objections, and the Department granted preclearance. The amended statute was to be effective August 28, 1995,21 but on August 22, a group of landowners and others sued for a declaration that the EAAA was facially unconstitutional. The district court issued a temporary restraining order the same day prohibiting the Authority from beginning operations. On November 27, 1995, the district court rendered judgment declaring the EAAA unconstitutional and permanently enjoining implementation of its provisions. But on direct appeal, this Court in Barshop v. Medina County Underground Water Conservation District held that the EAAA was not unconstitutional on its face and therefore reversed the district court’s judgment, dissolved the injunction, and remanded the case to determine whether attorney fees should be awarded.22 We issued our opinion and judgment on June 28, 1996, denied rehearing on August 16, 1996, and issued our mandate on February 10,1997.

The Authority began operations the day our opinion issued, taking over all the assets, offices, personnel, and papers of the District,23 which had continued in exis*397tence. A temporary board of directors appointed by the Legislature governed the Authority pending a November election.24 The Authority’s activities were widely reported in the media because of severe drought conditions existing in south central Texas,25 diverse interests competing for permits,26 and a lawsuit filed by the Sierra Club in June 1996 in the United States District Court for the Western District of Texas, seeking federal judicial management of the Edwards Aquifer to protect endangered species. On August 23. 1996, the federal court, convinced that it was facing an emergency, issued a preliminary injunction imposing a plan to manage the aquifer. The United States Court of Appeals for the Fifth Circuit stayed the injunction and later reversed it on the ground that the federal court should have abstained to allow the Authority, which was “in the process of taking comments and formulating rules for permits and emergency measures”, time to function.27

The EAAA directed the temporary board to “adopt rules governing the authority” “as soon as practicable.”28 On August 31, 1996, the Authority issued proposed rules to govern the process for filing a permit application, including a declaration of historical use29 The Authority set Saturday, December 28, 1996 — six months from the date of our Barshop opinion — as *398the filing deadline.30 In response to comments, the Authority moved the deadline to December 30, the following Monday.31 With few other changes, the Authority adopted the proposed rules on October 31, effective November 21,1996.32 As the Authority explained, although the initial rules did not lay out a complete permitting process, the Authority proposed them because it “believed it needed to provide notice to existing users as early as possible that December 30, 1996 will be the deadline for filing declarations of historical use.”33 On November 1, 1996, the Authority proposed further rules governing the process for reviewing permit applications,34 which did not become effective until February 18, 1997.35

The Authority took steps to publicize the December 30 deadline as widely as possible. Respondent Chemical Lime, Ltd.’s predecessor in interest, APG Lime Corp., received a permit application form by mail mid-November, noticed the December 30 deadline prominently printed at the top of the form, and began gathering the historical data needed to submit it. APG’s New Braunfels plant had been in operation since 1907, using limestone, water, and heat to manufacture lime used in purifying water and controlling sulphur emissions from coal-fired plants. For twenty-five years, the plant had used on average some 600 acre-feet — around 200 million gallons — of water a year.36 APG’s plant engineer, James Johnson, undertook to complete the permit application for the Authority but had trouble finding water usage data going back to 1972. In mid-December he telephoned the Authority to ask whether he could estimate water usage and was told he needed hard data. A few days before the deadline, he telephoned the Authority again to say that he would not be able to gather all the historical information in time. He was told that others were having problems, too, and that he should, as he recalled, “get it in when you get it — when you get that data on it.” Based on that conversation, Johnson believed he could submit the application late. He was not told that if the application was *399late, APG would lose its water, or that he could file an incomplete application by the deadline and supplement it later, which was the Authority’s policy.

APG did not file its permit until January 17, 1997. The Authority did not notice that it was late and continued to process it, notifying APG in April 1998 that a permit would issue for 618.2326 acre-feet of water. In 1999, Chemical Lime acquired APG’s plant and its interest in the permit application. Not until November 2000 did the Authority notify Chemical Lime that the application would be denied because it was filed after the deadline. Chemical Lime protested, but the Authority refused to reconsider.

Chemical Lime sued the Authority and its general manager and directors in their official capacities,37 seeking a declaration that the application deadline should have been set no sooner than six months from this Court’s denial of rehearing in Bar-shop, which would make Chemical Lime’s application timely. Alternatively, Chemical Lime sought a declaration that it had substantially complied with the EAAA’s permit requirements.38 The deadline-validity issue was presented to the trial court on stipulated facts. The court concluded that the EAAA “became effective on August 16, 1996”, the date rehearing was denied in Barshop; that the December 30, 1996 deadline “established by the Authority rule ... is not a valid, legal deadline”; that the proper deadline was February 16, 1997; and that Chemical Lime’s permit application was timely filed. The substantial-compliance issue was tried to a jury, which found for Chemical Lime. Based on its conclusions and the jury verdict, the trial court rendered judgment for Chemical Lime. The court awarded Chemical Lime $481,948.72 attorney fees, plus attorney fees on appeal.

The court of appeals affirmed but concluded that the permit application deadline should be six months from issuance of the mandate in Barshop, or August 10, 1997.39 The court “express[ed] no opinion regarding the legal status or validity of acts performed under color of the EAA Act between the June 28, 1996 supreme court judgment in Barshop and the court’s issuance of its mandate” on February 10, 1997.40 Having determined that Chemical Lime’s application was timely filed, the court did not reach Chemical Lime’s argument that it had substantially complied with the statutory permit requirements.41 The court affirmed the award of attorney fees to Chemical Lime.42

We granted the Authority and its *400agents’ petition for review.43 Because their interests are aligned, we refer only to the Authority in addressing their arguments.44 The Authority contends that (1) the December 30, 1996 permit application filing deadline was valid, (2) by missing the deadline Chemical Lime failed to substantially comply with the statutory requirements for a permit as a matter of law, (3) chapter 36 of the Texas Water Code precludes an award of attorney fees to Chemical Lime under the Declaratory Judgment Act and requires an award of attorney fees to the Authority. We address these arguments in turn.45

II

To determine the validity of the Authority’s December 30, 1996 permit application filing deadline, we begin with our decision in Barshop. One argument in that case against the constitutionality of the EAAA was that it set an impossible condition for compliance: a March 1, 1994 filing deadline that had expired before the Authority had even come into existence46 But the Legislature had amended the EAAA in 1995 to meet preclearance objections so that the Act could take effect, yet had not changed the deadline. So the argument had to be, not only that the deadline set by the EAAA turned out to be impossible, but that the Legislature intended — given its action in 1995 — to set an impossible deadline, so that when the EAAA took effect, it would prohibit any withdrawal of water from the Edwards Aquifer by regular permit. The argument was that the Legislature had created a regulatory scheme to preserve a crucial resource that was not only destined to fail but intended to fail. We characterized this argument as “nonsensical” and the logical result of it “absurd”.47

We explained the State’s position this way:

The State urges that we should interpret the March 1, 1994 date as directory rather than mandatory. The State maintains that we should consider the intent of the Legislature and construe this date to merely require that the declarations be filed with the Authority six months after the eventual effective date of the statute. We agree with the State.48

Thus, instead of adopting a “too literal construction of a statute, which would prevent the enforcement of it according to its true intent,”49 we took a more pragmatic approach. We noted that in Stephenson v. Stephenson,50 we had held that a statutory period for filing an appellate transcript with the newly created courts of civil appeals did not begin to run until “the appel*401late court clerk began operations”.51 “Similarly,” we held that “the March 1, 1994 deadline contained in the [EAAA] was intended to provide existing users six months to file their declarations of historical use.”52 Accordingly, we interpreted the EAAA “as requiring declarations of historical use to be filed six months after the Authority becomes effective.”53

Because of the prolonged delays in implementing the EAAA, it was not clear how long it would take the Authority to begin operations. In fact, the Authority took over from the District the same day our opinion in Barshop issued. The EAAA instantly transferred to the Authority all that was the District’s. Because the EAAA became effective immediately in a practical sense, the Authority read Barshop to require a filing deadline six months later, irrespective of further proceedings in this Court,54 although it extended the deadline two days from Saturday to Monday.55 Not only was the Authority under pressure to act expeditiously, it was concerned that any later deadline would be subject to challenge.56

Despite the fact that the Authority began operations June 28, 1996, Chemical Lime argues, as the court of appeals held, that the EAAA did not become “effective” within the meaning of Barshop until the mandate issued in that case on February 10, 1997. Chemical Lime points to Rule 18.6 of the Texas Rules of Appellate Procedure, which provides that “[t]he appellate court’s judgment on an appeal from an interlocutory order takes effect when the mandate is issued.” Chemical Lime argues that the same rule should apply in an appeal from a final judgment. Alternatively, Chemical Line argues that the EAAA did not become effective until rehearing was denied in Barshop on August 16, 1996. But none of these arguments find support in Barshop itself. As Chemical Lime properly acknowledges, Bar-shop’s approach to resetting the filing *402deadline was entirely pragmatic.57 Bar-shop set a new filing deadline based not on the legal effect of some procedural occurrence in that case but on the practical reality of the Authority’s commencement of operations.

Further in the alternative, and focusing instead on practicalities, Chemical Lime argues that since the Legislature’s intent in the EAAA was, as we stated in Bar-shop, “to provide existing users six months to file their declarations of historical use”,58 the period should run from the effective date of the Authority’s rules governing the application process — November 21, 1996 — or at the earliest, from the date those rules were proposed — August 31, 1996. But this is an argument, not that the Authority misconstrued Barshop, but that Barshop was wrongly decided. There is nothing to indicate that the inevitable delay in promulgating rules would have been any less had the EAAA taken effect in 1993. It was never possible for final rules to be in effect six months before the filing deadline. Nor did the lack of final rules hamper the filing process. The difficulty applicants faced lay not in any uncertainty over what rules would apply but in gathering the required data on water use. Out of more than a thousand applications the Authority received, only twenty-two were late, and there is no evidence that any delay was attributable to the promulgation of the Authority’s rules.

The parties have devoted much attention to the problems in determining when, as a general matter, an appellate court decision takes effect. The concurring opinions shed helpful light on these problems and strongly suggest that this is an aspect of Texas appellate procedure that could well benefit from more definite rules and procedures. We conclude, however, that this case turns not on when our decision in Barshop became effective, but when the Authority became effective. On that issue, the facts leave no doubt that the Authority permissibly set the permit application filing deadline at December 30,1996.

Ill

The jury found that Chemical Lime substantially complied with the EAAA’s permit application requirements, and the trial court rendered judgment on their verdict. The Authority contends that Chemical Lime failed to substantially comply with the statutory requirements as a matter of law. The issue was not addressed by the court of appeals, but it has been briefed in this Court, and we elect to resolve it.

The doctrine of substantial compliance, though certainly familiar to the law, lacks comprehensive definition, so we begin with several limiting assumptions based on what the parties here do and do not argue. We assume, because the Authority does not argue to the contrary, that the EAAA does not require strict compliance with permit application requirements. The assumption is a reasonable one, since one of the EAAA’s express requirements is that a “declaration of historical use must be filed ... on a form prescribed by the board [of directors]”,59 though there is nothing to indicate that filing the same information on plain paper *403would require rejection of the application. We also assume that substantial compliance with a statute means compliance with its essential requirements, since the parties agreed that this was a correct statement of the law for the jury charge. We assume further, to the extent it is relevant, again because the Authority does not argue otherwise, that Chemical Lime tried in good faith to file its permit application by the deadline. Although it would seem that a person who meets essential statutory requirements has substantially complied, even if not acting in complete good faith, it is clear that a person’s good faith is not enough for substantial compliance when essential statutory requirements like a deadline are not met. Finally, since the Authority initially approved Chemical Lime’s application before noticing that it was late-filed, we assume that Chemical Lime complied with all statutory requirements except the December 30, 1996 filing deadline — that is, that Chemical Lime is an existing user that established by convincing evidence beneficial use of underground water from the aquifer during the 21-year period before June 1993. Since the Authority barely mentions late payment of the fee, the question we decide boils down to this: did the Legislature consider the permit application filing deadline essential to the EAAA?

We think the answer must be yes. To be clear, the issue is not whether Chemical Lime substantially complied with the filing deadline. A deadline is not something one can substantially comply with. A miss is as good as a mile.60 As the United States Supreme Court has explained:

The notion that a filing deadline can be complied with by filing sometime after the deadline falls due is, to say the least, a surprising notion, and it is a notion without limiting principle. If 1-day late filings are acceptable, 10-day late filings might be equally acceptable, and so on in a cascade of exceptions that would engulf the rule erected by the filing deadline; yet regardless of where the cutoff line is set, some individuals will always fall just on the other side of it. Filing deadlines, like statutes of limitations, necessarily operate harshly and arbitrarily with respect to individuals who fall just on the other side of them, but if the concept of a filing deadline is to have any content, the deadline must be enforced. Any less rigid standard would risk encouraging a lax attitude toward filing dates. A filing deadline cannot be complied with, substantially or otherwise, by filing late — even by one day.61

Rather, the issue is whether Chemical Lime substantially complied with the permit application process, one requirement of which was the filing deadline.

The importance of a fixed filing deadline is apparent in the EAAA. The Legislature picked a specific, calendar date by which permit applications were required to be filed. It did not delegate that responsibili*404ty to the Authority. It made no provision for extensions and did not empower the Authority to do so. Its intent that applicants strictly adhere to the deadline is thus fairly clear. Though it became necessary for this Court to reset the deadline to preserve the constitutionality of the EAAA, it was not necessary, nor would it have been proper, to change the character of the new deadline, making it less mandatory than the Legislature originally intended.

The need for a filing deadline, with no exceptions, is also apparent. The Legislature found it necessary to cap annual water withdrawals to protect the aquifer. Because applications would exceed the cap, with no fixed cutoff, the Authority would be required to constantly readjust allocations among permittees to provide for late applicants. Indeed, the Authority argues that if Chemical Lime’s application is deemed timely and approval required, all permits must be adjusted, albeit slightly (about 0.1%62), for total annual withdrawals from the aquifer to remain at the statutory limit. The Legislature could certainly have concluded that such readjustments should be avoided.

Had Chemical Lime filed an incomplete or inaccurate application, its argument for substantial compliance would be stronger, even though as a practical matter, it would make no discernible difference to the permitting process whether an application was amended after the deadline or filed a few days late. But a line must be drawn somewhere, and the Legislature was not required to draw it with perfect precision. Chemical Lime points out that in Barshop we agreed with the State that the March 1, 1994 filing deadline in the EAAA was “directory rather than mandatory”.63 Chemical Lime contends that the law permits substantial compliance with non-mandatory filing deadlines. But in Barshop, we held only that the expired deadline was directory because, as we have already explained, any other reading would have led to an absurd result. We did not suggest that a viable deadline would also be merely directory.

Although the EAAA states that a declaration of historical use “must be filed” by the deadline,64 Chemical Lime argues that because the EAAA prescribes no penalty for late filing, the deadline should not be treated as mandatory. We have said that “[t]he word ‘must’ is given a mandatory meaning when followed by a noncompliance penalty”65 but this does not suggest that when no penalty is prescribed, “must” is non-mandatory. “When the statute is silent [regarding the penalty for noncompliance], we have looked to its purpose for guidance.”66 The EAAA does not suggest that an applicant can be fined for a late filing or that the water allocated should be reduced accordingly. The only penalty the EAAA suggests is that late applications will not be considered.

We recognize the hardship of this penalty to Chemical Lime, but we believe the *405EAAA requires a firm deadline. Chemical Lime’s late filing did not substantially comply -with the statute’s permitting requirements.

IV

The trial court awarded Chemical Lime attorney fees under the Declaratory Judgment Act (DJA). The Authority argues that it can be sued only under chapter 36 of the Texas Water Code, and that chapter does not provide for recovery of attorney fees by the plaintiff. While section 36.251 does provide for suit against the Authority,67 section 36.254 states that that remedy “do[es] not affect other legal or equitable remedies that may be available.” The Authority has not advanced an argument why we should not take section 36.254 at its word. Nor does the Authority argue that the DJA permits an award of attorney fees only to a prevailing party, an issue on which we express no opinion.68 The Authority does not challenge the reasonableness or necessity of the fees awarded by the trial court.69 But an award must be equitable and just,70 considerations addressed to the trial court’s discretion.71 Now that Chemical Lime is no longer the prevailing party, the trial court should have the opportunity to reconsider its award.

Because the Authority has prevailed, it is entitled to attorney fees under section 36.066(g) of the Water Code.72 The parties stipulated below to the amount of those fees.73

V

Accordingly, the court of appeals’ judgment is reversed and the case is remanded to the trial court for further proceedings consistent with this opinion.

Justice BRISTER filed a concurring opinion.

Justice WILLETT filed a concurring opinion.