ORDER
On February 11, 1994, appellant Owens-Corning Fiberglas Corporation tendered a transcript to the Clerk of this Court for *404 filing. Pursuant to Texas Rule of Appellate Procedure 56(a), the Clerk referred the matter of whether the appeal had been properly perfected to the Court. We conclude that the appeal has been properly perfected and will order the transcript filed.
I. DISCUSSION
The question we must decide is which of two judgments is the trial court’s final judgment. See Tex.R.Civ.P. 301 (only one final judgment shall be rendered in any cause except when otherwise specifically provided by law). On October 14,1993, the trial court signed its first judgment in this cause. On October 20, 1993, the trial court signed a second judgment. The two judgments are identical except for the date signed. Owens-Coming seeks to appeal from the trial-court judgment signed October 20, 1993.
On November 19, 1993, Owens-Coming filed a motion for new- trial. Tex.R.Civ.P. 329b(a). On January 18, 1994, Owens-Corning filed its cash deposit in lieu of appeal bond. Tex.R.App.P. 40(a)(1). If the October 20 judgment is the trial court’s final judgment, Owens-Coming filed a timely motion for new trial and timely perfected its appeal. If the October 14 judgment is the trial court’s final judgment, Owens-Corning’s motion for new trial was not timely and did not extend the time to perfect the appeal. If the October 20 judgment modified, corrected, reformed, or vacated the October 14 judgment, then the October 20 judgment (1) superseded the October 14 judgment, (2) is the trial corut’s final judgment, and (3) extended the appellate timetables.
A. Did the October 20 Judgment Modify, Correct, or Reform the October 14 Judgment?
The October 20 judgment modified, corrected, or reformed the October 14 judgment if (1) the trial corut acted within its period of plenary power when it signed the October 20 judgment, (2) the signatory date is a part of the judgment, and (3) the trial court’s action in signing the October 20 judgment did not impermissibly enlarge the time to file a motion for new trial.
1. Trial Court May Modify, Correct, Reform, or Vacate its Judgment During Its Period of Plenary Power.
A trial court has plenary power to reverse, modify, or vacate its judgment at any time before it becomes final.
Mathes v. Kelton,
2. Is the Signature Date a Part of the Judgment Such That Signing a Second Judgment That Changes Only the Signature Date Extends the Appellate Timetables?
a. The Signature Date is a Part of the Judgment.
The date a judgment or order is signed determines the beginning of the periods prescribed by the Texas Rules of Civil Procedure for the court’s plenary power to grant a new trial or to vacate, modify, correct, or reform a judgment or order. Tex. R.Civ.P. 306a(l). Although the absence of a showing of the date of signing does not invalidate a judgment, its omission is treated as a
clerical error
that may be
corrected
by judgment nunc pro tunc. Tex.R.Civ.P. 306a(2);
Cyrus v. State,
b. A Second Judgment That Changes Only The Signature Date Extends Appellate Timetables.
■ If a judgment is modified, corrected, or reformed
in any respect,
the time for appeal shall run from the time the modified, corrected, or reformed judgment is signed. Tex.R.Civ.P. 329b(h).
Any change,
whether material or substantial, made in a judgment while the trial court retains plenary power, operates to delay the start of the appellate timetables until the date , the modified, corrected, or reformed judgment is signed.
Check v. Mitchell,
3. When Does A Changed Signatory Date Not Extend Appellate Timetables?
We begin by reviewing
pre-Check
cases in which a second judgment signed during the trial court’s period of plenary power and identical to the first except for the signature date did not extend the appellate timetables.
Anderson v. Casebolt,
In
Casebolt,
the trial court rendered two judgments that were identical except for the signatory date.
Casebolt,
a. Terms of Court & Plenary Power
The source for the rule announced in Case-bolt is Texas Rule of Civil Procedure 5. Rule 5 provides, in pertinent part: “The court may not enlarge the period for taking any action under the rules relating to new trials except as stated in these rules.” 3 Rule 5’s prohibition against enlarging the time to file a motion for new trial limits the trial court’s plenary power.
Before the adoption of Texas Rule of Civil Procedure 329b, the trial court’s plenary power continued until the end of the term of court in which the judgment was rendered, at which time the judgment became final.
4
The period within which a trial court could exercise its inherent power was modified in certain specified courts by the so-called Special Practices Act [hereinafter Act]
5
and later, by the Texas Rules of Civil Procedure.
Humble Exploration Co. v. Browning,
In 1941, the Texas Rules of Civil Procedure became effective. The rules and subsequent amendments broadened the application of the Act in the district courts. The 1955 revisions to rules 320 and 330 and the adoption of new rules 329a and 329b sought to achieve uniformity of practice in all district courts with respect to motions for new trial. Id. This goal was finally achieved when noncontinuous terms in the district courts were abolished. See Act of May 6,1955, 54th Leg., R.S., ch. 297, § 1, 1955 Tex.Gen.Laws 806, 806 (Tex.Civ.Stat.Ann. art. 1919, § 1, since repealed, see now Tex.Gov’t Code Ann. § 24.012 (West 1988)). 6
b. Purpose of Rule 5’s Prohibition Against Enlargement of Time
The rules setting the timetables relating to motions for new trial and for taking appeal
*407
are meant to provide a uniform time when a judgment is final and to eliminate the uncertainty that was associated with tying the trial court’s period of plenary power to the term of court.
See
Tex.R.Civ.P.Ann. 329b cmt (West 1977). Rule 5 prevents the trial court from using its plenary power to circumvent the timetables relating to new trials and thereby undermine the rules’ underlying purposes.
See Humble,
c. Scope of Rule 5’s Prohibition
Every time a trial court signs a modified, corrected, or reformed judgment, the time to file a motion for new trial is extended because the date the second judgment is signed becomes the date from which the time to file a motion for new trial is computed. Tex.R.CivJP. 329b(h). Rule 329b(h) and Rule 5 do not conflict, however, because Rule 5 allows the trial court to enlarge the period for taking action under the rules relating to new trials if the rules make provision for such enlargement. Thus, the trial court can enlarge the time to file a motion for new trial by correcting, modifying, or reforming its judgment during its period of plenary power, with certain limitations. Tex.R.Civ.P. 329b(h);
Check,
In
A.F. Jones, Vander Stucken, Chantre, Martinez,
and
Bellmead
(the authorities relied on in
Casebolt),
the trial court’s signing of the second judgment had the effect of enlarging the time to file a motion for new trial or perfect an appeal after the time to do so had expired under the rules setting those timetables, even though the court’s plenary power had not yet expired.
See also Nolan,
Casebolt
has been more broadly applied.
See Mackie v. McKenzie,
d. The Original Scope of Rule 5’s Prohibition Has Narrowed With Changes in Timetables Governing Motions For New Trial and Time to Appeal.
When Casebolt was decided, the Texas Rules of Civil Procedure prescribed deadlines for the filing of a motion for new trial and for perfecting appeal that passed before the trial court’s plenary power over its judgment expired. 9 Today, a trial court no longer retains plenary power over its judgment after the time to file a motion for new trial or to perfect appeal has expired in the “ordinary appeal.” 10 The trial court’s period of plenary power over its judgment and the last day to file a motion for new trial or perfect appeal are the same: thirty days after the date the judgment is signed. See Tex. R.Civ.P. 329b(a), (d); Tex.R.App.P. 41(a). In only one instance does the deadline to perfect an appeal expire before the end of the trial court’s period of plenary power. In an “extended appeal” (one in which either (1) a motion for new trial or to modify, correct, or reform the judgment, or (2) a request for findings of fact and conclusions of law is filed), the appellant must perfect the appeal within ninety days after the date the judgment is signed. See Tex.R.App.P. 41(a)(1). If a motion for new trial or to modify, correct or reform the judgment is overruled on the seventy-fifth day after the judgment is signed, either by order or by operation of law, the trial court’s period of plenary power to change its judgment continues to the 105th day after the date the judgment was signed. 11 See Tex.R.Civ.P. 329b(e); Tex. R.App.P. 41(a). In such a situation, Casebolt may prohibit the trial court from rendering an order after the ninetieth day that simply affirms its former judgment thereby giving an aggrieved party a new opportunity to perfect an appeal after the initial ninety-day opportunity was lost. We do not decide this question, however, because it is not presented here.
4. Was The Sole Purpose of the October 20 Judgment to Enlarge the Time for Appeal?
In
Casebolt,
the supreme court concluded that the second judgment served no other purpose than to enlarge the time for appeal and based this conclusion on a recital in the trial court’s second order.
Casebolt,
Neither the October 20 judgment nor the record in this cause indicate that the trial court’s purpose in signing the October 20 judgment was to extend the time to file a motion for new trial or perfect an appeal. The second judgment was signed only six days after the first and more than three weeks before the deadline to file the motion for new trial. Nothing in the record on or before October 20, 1993, indicated that Owens-Corning would fail to file a motion for new trial within thirty days after the October 14 judgment.
Moreover, we question whether it can ever be said that the sole purpose of a second judgment is to enlarge the appellate timetables, absent an express indication in the record. Consider, for example, the effect of a second judgment on the award of post-judgment interest. Here, the October 20 judgment, in addition to extending the appellate timetables, affected the date from which postjudgment interest accrued. The October 20 judgment recites that “postjudgment interest on the amounts owed by defendant to plaintiffs’ shall accrue at the rate of TEN PERCENT (10%) per annum from the date the judgment is signed until it is satisfied pursuant to Tex.Rev.Civ.Stat.Ann. art. 5069-1.05, §§ 2 and 3.” See Tex.Rev.Civ.Stat.Ann. art. 5069-1.05, § 3 (West Supp.1994). Thus, the trial court’s October 20 judgment changed the amount of postjudgment interest that accrued and did not merely affirm the first judgment.
Additionally, it is possible that the trial court signed the October 20 judgment because the signature date of the October 14 judgment was incorrect. 13 On this record, we are unable to conclude that the October 20 judgment served no other purpose than to extend the appellate timetable.
5. The October 20 Judgment Modified, Corrected, or Reformed the October 14 Judgment.
Casebolt
was decided before the addition of subsection (h) to Rule 329b and the decision in
Check. Casebolt
construes Rule 5 and
Check
construes Rule 329b. As a general rule of construction, the rules must be harmonized when possible.
See Ex parte Godeke,
Casebolt
does not stand for the proposition that a second judgment identical to the first except for the signatory date is insufficient to extend the appellate timetables.
Casebolt,
Rather, the
Casebolt
analysis should focus on whether a trial court renders an order simply affirming a former judgment (1) after its period of plenary power has expired or (2) during its period of plenary power but after the time to file a motion for new trial or perfect an appeal has expired and the record indicates that the sole purpose of the order was to extend the appellate timetables.
Casebolt,
Here, the second judgment was signed six days after the first judgment; that is, the trial court signed the October 20 judgment during its period of plenary power and before any applicable deadline for filing a motion for new trial or perfecting an appeal had passed. The record is silent as to the trial court’s intent or purpose in signing the October 20 judgment. We hold that the October 20 judgment modified, corrected, or reformed the October 14 judgment.
B. Did the October 20 Judgment Vacate the October 14 Judgment?
1. The Rule in Mullins v. Thomas
Neither the October 20 judgment nor the record in this cause demonstrate the trial court’s intent to vacate the October 14 judgment. In
Mullins v. Thomas,
It is not necessary, however, that the second judgment expressly state that the first judgment is vacated.
See B & M Mach. Co. v. Avionic Enters, Inc.,
2. Harmonizing Mullins and Check
Check
construed Rule 329b(h).
Mullins
is based on the one-final-judgment rule carried forward in Rule 301.
Check
did not expressly overrule
Mullins.
If we assume that
Check
did not implicitly overrule
Mullins,
then
Check
and
Mullins
must be
*411
read in a manner that harmonizes the rules and so that the right to appeal is not lost by creating a requirement not absolutely necessary from the literal language of the rules.
Jamar,
Neither Rule 329b(h) nor
Check
require that the modified, corrected, or reformed judgment indicate the trial court’s intent to vacate the first judgment before the second judgment will be given effect. We believe that the supreme court’s promulgation of Rule 329b(h) and its decision in
Check
mean that
any
change in a judgment made by the trial court during its period of plenary power should be treated as a modified, corrected, or reformed judgment that presumptively vacates the trial court’s former judgment unless the record indicates a contrary intent. Crofts, 20 Tex.Tech L.Rev. at 1148 (supreme court obviously meant in
Check
that subsequent judgments incorporating even immaterial and insubstantial changes qualify as modified judgments which presumably vacate pre-existing judgment by implication).
See also Alford v. Whaley,
CONCLUSION
We hold that the October 20 judgment operated to start the appellate timetables on the date it was signed. Thus, Owens-Coming timely filed its motion for new trial and cash deposit in lieu of appeal bond. Accordingly, we order the transcript filed as of the date received, February 11, 1994, and the first and second supplemental transcripts filed as of March 4, 1994, and March 25, 1994, respectively.
It is so ordered.
Notes
. For purposes of timing the appellate steps, the judgment was deemed rendered the day signed.
Anderson v. Casebolt,
. In Casebolt, the trial court attempted to vacate its first judgment thirty-three days after its rendition, action the trial court no longer had the power to take under the rules of civil procedure. Thus, on its facts, Casebolt stands for the proposition that the trial court lacked the power to vacate its first judgment and render the second judgment because (1) the trial court’s period of plenary jurisdiction had passed and (2) the first judgment had become final. Inexplicably, the supreme court did not expressly state that this was the basis for holding that the second judgment did not extend the time for appeal. The facts in Casebolt have no application to our case because, here, the trial court rendered its second judgment before its plenary power expired and the first judgment became final. Even so, we must further consider Casebolt because it is often cited for an entirely different procedural principle.
.At the time Casebolt was decided, Rule 5 provided, in pertinent part, that the court may not:
enlarge the period for taking any action under the rules relating to new trials or motions for rehearing except as stated in the rules relating thereto or the period for taking an appeal or writ of error from the trial court to any higher court or the period for application for writ of error in the Supreme Court, except as stated in the rules relating thereto;
Tex.R.Civ.P. 5, 33 Tex.BJ. 703 (1970, since amended 1972, 1975, 1986, 1990). Rule 5 was amended to delete all references to appellate procedure when the Texas Rules of Appellate Procedure were adopted by order of April 10, 1986, effective September 1, 1986. See 49 Tex. B.J. 600 (1986, amended 1990). Today, the rule provides, in pertinent part: "The court may not enlarge the period for taking any action under the rules relating to new trials except as stated in these rules.” Tex.R.Civ.P. 5. Accordingly, the sole prohibition at issue is whether the trial court impermissibly attempted to enlarge the time to file a motion for new trial.
. For a discussion of the problems associated with this system, see Tex.R.Civ.P. 329b cmt. (West 1977).
. Act approved Mar. 21, 1923, 38th Leg., R.S., ch. 105, sec. 1, art. 1969a, § 16, 1923 Tex.Gen. Laws 215, 221 (1911 Tex.Rev.Civ.Stat. art. 1969a, § 16, since amended, repealed, and reenacted; see now Tex.R.Civ.P. 330, 329a, 329b).
. The elimination of the jurisdictional effects of terms of court in the county courts did not parallel developments in the district courts. The 1961 amendments of Rules 329a and 329b made district-court practice with respect to pending and unfinished matters and motions for new trial applicable in county courts in so far as possible. Tex.R.Civ.P.Ann. 329b cmt. (West 1977); see Tex.R.Civ.P. 329a, 329b, 23 Tex.B.J. 619, 681-82 (1960).
.
Nolan,
. In
Mackie,
the trial court rendered an interlocutory summary judgment and then rendered an order nonsuiting the defendant’s remaining counterclaim. The trial court then rendered a second judgment within the court's period of plenary power and before the time to file a motion for new trial or perfect appeal had expired. This second judgment, entitled "Final Judgment,” "found” that the summary judgment was final after the counterclaim was dismissed, and ordered that the summaty judgment was “hereby made final.”
Mackie
relied on
Casebolt
for the proposition that the new judgment served no other purpose than to extend the appellate timetables and was without effect.
Mackie v. McKenzie,
.Rule 329b formerly provided, in pertinent part:
1. A motion for new trial when required shall be filed within ten (10) days after the judgment or other order complained of is rendered.
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5. Judgments shall become final after the expiration of thirty (30) days after the date of rendition of judgment or order overruling an original or amended motion for new trial.
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... The failure of a party to file a motion for new trial within the ten (10) day period prescribed in subdivision 1 of this rule shall not deprive the court of jurisdiction to set aside a judgment rendered by it, provided such action be taken within thirty (30) days after the judgment is rendered. The filing of a motion for new trial after ten (10) days have expired and before thirty (30) days have expired since the rendition of the judgment shall not operate to extend the court’s jurisdiction over the judgment for a period of more than thirty (30) days from the date of the rendition of judgment.
Tex.R.Civ.P. 329b(l), (5), 29 Tex.B.J. 735, 779 (1966, since amended 1973, 1977, 1980, 1983, 1987) (emphasis added).
Tex.R.Civ.P. 353(a) formerly provided, in pertinent part:
(a) An appeal, when allowed by law, may be taken by notice of appeal ... such notice to be given or filed within ten days after judgment or order overruling motion for new trial is rendered.
Tex.R.Civ.P. 353(a), 25 Tex.B.J. 371, 432 (1962, since amended 1975, 1980, and repealed 1986).
. An “ordinary appeal” refers to an appeal where no motion or request has been filed that operates to extend the beginning of the appellate timetables beyond thirty days from the date the judgment is signed.
. One way to eliminate this fifteen-day "window” would be to amend Rule 329b(c), replacing “seventy-five days” with "sixty days."
. We will assume, for purposes of discussion, that the trial court’s purpose in signing a second judgment is a valid consideration in determining whether to give effect to the October 20 judgment. Although nothing in Rule 5 relates to the reason for rendering a second judgment, the purpose of Rule 5’s prohibition against enlarging time is to prevent the trial court from using its plenary power to circumvent the timetables relating to motions for new trial set forth in the rules, thereby undermining the rules’ purpose in providing certainty to the finality of judgments.
. It is also possible that the trial judge simply forgot he had signed the October 14 judgment when he signed the October 20 judgment.
. Although the supreme court in
Mullins
did not discuss the legal rationale underlying this principle, it cited to the authorities in the court-of-civil appeals opinion.
Mullins,
. Several courts have followed
Mullins
when confronted with a second-judgment problem.
See Azbill v. Dallas County Child Protective Servs. Unit,
