SHIRLEY S. ABRAHAMSON, C.J.
¶ 1. This is a review of an unpublished decision of the court of appeals affirming an order of the circuit court for Milwaukee County, Christopher R. Foley, Judge.1
¶ 2. The issue presented in this case is whether a circuit court may, pursuant to Wis. Stat. § 938.365(6),2 extend a juvenile's one-year dispositional order temporarily for 30 days if the 30-day extension order is entered after the one-year dispositional order has expired.
¶ 3. We hold that after a juvenile's one-year dis-positional order expires, a circuit court may not grant a 30-day temporary extension of the order under Wis. Stat. § 938.365(6). Further, consistent with caselaw, the expiration of the one-year dispositional order cannot be waived. Because no 30-day temporary extension or new dispositional order was granted prior to the expiration of the one-year dispositional order, the circuit court could not act with respect to Michael S. once the one-year dispositional order expired.
I — i
¶ 4. We must first address the issue of mootness. On April 11, 2005, Michael S. turned 18 and is no longer subject to the juvenile code.
[6]*6¶ 5. A determination of the issue presented in the instant case will have no practical effect on Michael S. With regard to Michael S., the issue raised on review is therefore moot.
¶ 6. Reviewing courts generally decline to decide moot issues but may do so under certain circumstances.3 A court may decide a moot issue when the issue is of great public importance; occurs frequently and a definitive decision is necessary to guide the circuit courts; is likely to arise again and a decision of the court would alleviate uncertainty; or will likely be repeated, but evades appellate review because the appellate review process cannot be completed or even undertaken in time to have a practical effect on the parties.
¶ 7. The question presented in this case seems to satisfy all these exceptions to the mootness rule. Deciding a circuit court's retention of authority over a juvenile after the expiration of a dispositional order is a matter of great importance to the sound operation of the judicial system and the rights and interests of juveniles.
¶ 8. We will therefore address the issue presented in the instant case.
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¶ 9. We now turn to the relevant facts relating to the expiration and extension of Michael S.'s disposi-tional order.
¶ 10. The district attorney's office for Milwaukee County petitioned the circuit court for Milwaukee County on August 22, 2001, seeking to adjudicate [7]*7Michael S. delinquent. Michael S. waived his right to a trial, and on Novemher 8, 2001, the circuit court entered a dispositional order placing Michael S. on supervision until October 23, 2002. The November 8 order contained a number of conditions of supervision with which Michael S. was required to comply.
¶ 11. On September 10,2002, the State petitioned the circuit court for a change in the original disposi-tional order. This requested change was based on post-November 8 conduct violating Michael S.'s conditions of supervision. Specifically, the State sought to place Michael S. in a secure group home (change of placement) and sought a one-year extension of the original one-year dispositional order set to expire on October 23, 2002.
¶ 12. At a hearing before Judge Christopher Foley on October 2, 2002, Michael S.'s attorney, the Assistant District Attorney, and Michael S.'s probation officer discussed the status of the State's petition and set a date for a contested hearing on the petition. Michael S. did not oppose an extension of supervision but did oppose a change of placement, and this objection would be the subject of the contested hearing.
¶ 13. During the discussion about setting the date for the contested hearing, the following exchange took place, indicating that the hearing could not be held before October 24:
[PROBATION OFFICER]: I have a quick comment, Judge. I'm on vacation starting this Friday until the 15th. If that's going to be a problem, if we want a quick hearing—
THE COURT: We have problems with quick hearings all over the place. As some of you may be aware, we finished a 7 day jury trial on a TPR [termination of [8]*8parental rights] last night at 8 o'clock. We're starting another one that's projected to last at least five days on Monday. We are institutionally trying to figure out how we can possibly handle the requirements for preliminary hearings on 13 or more kids that we anticipate are going to be charged with homicides in a 10-day period. I don't know how we're going to do that. And I'm going to the judicial conference. So, a quick hearing is a foreign concept here.
THE COURT: ... Let's get a date, please.
THE CLERK: What is this being set for? A contest hearing?
THE COURT: Yes.
THE CLERK: October 24th at 1:30?
[MICHAEL S.'S ATTORNEY]: I can't do it on the 24th. I can do it on the 25th any time.
[ASSISTANT DISTRICT ATTORNEY]: Do you have anything the following week?
[MICHAEL S.'S ATTORNEY]: The following week I'm out of town, the week of the 28th. The 24th is good in the morning. I don't know what — I just can't do it in the afternoon.
¶ 14. The parties agreed that the contested hearing would be held at 10:30 A.M. on October 24, 2002. Michael S.'s attorney also discussed at the October 2 hearing the possibility of getting another psychological evaluation for Michael S.; apparently this evaluation was never done.
¶ 15. On October 24, 2002, the parties met before Judge Michael Malmstadt; Judge Foley was occupied with a jury trial. At the October 24 hearing were [9]*9Michael S., his attorney, his mother and grandmother, the assistant district attorney assigned to the case, the probation officer, and three individuals involved in various juvenile delinquency programs.
¶ 16. To familiarize himself with the status of Michael S.'s case, Judge Malmstadt questioned Michael S. and the attorneys. The parties discussed at length the possible placement options and whether Michael S. was going to change his behavior.
¶ 17. Without either attorney raising the issue, Judge Malmstadt noticed that Michael S.'s dispositional order had expired on October 23, 2002, the prior day. The import of the expiration date of the dispositional order was not lost on Judge Malmstadt. The following relevant exchange relating to the dispositional order ensued:
JUDGE MALMSTADT: Okay. I'm being told his Probation ended yesterday?
[PROBATION OFFICER]: I believe so. Unless — I don't know if Judge Foley extended it verbally or not last time. I didn't hear.
[ASSISTANT DISTRICT ATTORNEY]: Placed on Probation October 23, 2001.
JUDGE MALMSTADT: Okay.
[MICHAEL S.'S ATTORNEY]: Only was a one-year Order. I have the Original Dispositional Order. That should be in the file.
[ASSISTANT DISTRICT ATTORNEY]: What does the Judgment roll say?
JUDGE MALMSTADT: ... I don't see anything in it that shows there was ever an Extension.
[10]*10[ASSISTANT DISTRICT ATTORNEY]: My notes are silent to that as well.
[MICHAEL S.'S ATTORNEY]: Original Order says "Ends 10/23/02." Signed by [Judge] Wasielewski. My notes reflect we set this for Contest, argued placement, got a copy of the Psych. I don't have anything about extending it.
JUDGE MALMSTADT: Do you know what that all means, Michael?
[MICHAEL S.]: (Nods head negatively.)
JUDGE MALMSTADT: Well, I will tell you,- in a nut shell, what it means. It means you have two choices right now. Okay?
Choice Number One— And I'm going to go through this damn thing with a fíne tooth comb, to make sure it's true.
But, Choice Number One, tells me you are off Probation, that we have no more authority over you, and it's "Good Bye, Michael."
Well, that's one option.
The other option is for you to say: 'You know what? I think I want this Judge to extend my Probation so I can work with the people from Running Rebels." I can only do that if you say, "Judge, I want to you to do that." I can't make you do that. That's up to you.
Those are your two options.
[MICHAEL S.]: The first.
JUDGE MALMSTADT: Fine. Back to Detention. I'm going to show this to Judge Foley. Judge Foley and I will talk about it. And if Judge Foley and I come to the same conclusion, I think this case is over with.
[11]*11¶ 18. Judge Malmstadt understood the expiration of Michael S.'s one-year dispositional order to mean that the circuit court's authority over Michael S. may have ceased on October 23, saying: "Well, if he is off supervision, what authority do I have to keep him?"
¶ 19. Prior to concluding the hearing, Judge Malmstadt checked to determine whether any files showed a temporary extension of the one-year disposi-tional order. They did not. Judge Malmstadt also stated that he would check further with court reporters to determine whether the one-year dispositional order had been temporarily extended at the October 2, 2002, hearing.
¶ 20. That afternoon the parties appeared before Judge Foley. Michael S.'s attorney was not present. Judge Foley stated that at none of the previous three hearings (September 24, September 26, and October 2) was there any indication "that a 938.365(6) extension was granted. And Judge Malmstadt was concerned that this Court may have lost authority to act in this matter."
¶ 21. Judge Foley further stated that, after speaking with the court reporters for the previous three hearings, he was satisfied that no judge had orally temporarily extended Michael S.'s one-year disposi-tional order.
¶ 22. Judge Foley concluded, however, that the failure to extend the order was not significant, because Wis. Stat. § 938.365(6) had been modified to mean that if a juvenile does not object to the scheduling of a hearing beyond the expiration of the one-year disposi-tional order, "it operates as a waiver." Judge Foley asserted that his reading of § 938.365(6) was supported by the text of § 938.315(3), providing that "failure to comply with any time limit specified in this chapter [12]*12does not deprive the court of personal or subject matter jurisdiction or of competency to exercise that jurisdiction."4
¶ 23. Judge Foley went on to conclude that "I continue to have authority in this matter, that I have the right to, in effect, retroactively grant the thirty days' extension, which I am doing." Michael S.'s attorney was not present and was not on the phone with the court during this brief hearing.
¶ 24. At a hearing later that same day, Michael S.'s attorney was present by phone. Judge Foley explained to Michael S.'s attorney that he had granted the temporary extension pursuant to Wis. Stat. § 938.365(6) and § 938.315(3). A subsequent hearing date was set for November 8, 2002, and just before the close of the hearing Michael S.'s attorney asked for the statute numbers Judge Foley had mentioned earlier in the hearing (§§ 938.365(6) and 938.315(3)). According to Michael S.'s attorney, this, phone appearance on October 24, 2002 took only a couple of minutes.
¶ 25. At the November 8, 2002 hearing, a third judge, Judge Joseph R. Wall, presided. Michael S.'s attorney objected to Judge Foley's temporary extension of Michael S.'s one-year dispositional order, contending that the circuit court's authority expired on October 23, 2002. Judge Wall concluded that unless the transcript from the October 2 hearing demonstrated that Judge Foley had extended the one-year dispositional order, the court lost authority over Michael S. on October 23, 2002. Concerned about this issue, Judge Wall ordered Michael S. placed in detention until Judge Foley could review, on November 26, 2002, the issue of the expiration of the one-year dispositional order.
[13]*13¶ 26. At the November 26 hearing before Judge Foley, the parties discussed the implications of the circuit court's failure to extend the one-year disposi-tional order temporarily for 30 days on October 2, 2002, and the circuit court's authority under Wis. Stat. §§ 938.315(3) and 938.365(6). In affirming his earlier assertion that the circuit court retained authority over Michael S., Judge Foley acknowledged that he never said the "magic words" ordering an extension. The judge reasoned that because there was good cause for scheduling the hearing on October 24 as opposed to October 23, the circuit court did not have to state explicitly on October 2 that Michael S.'s one-year dispositional order was being extended temporarily for 30 days.
¶ 27. Judge Foley asserted that the circuit court inferentially granted the 30-day temporary extension when the matter was set on the court's calendar for October 24, 2002. Judge Foley's ruling that the temporary extension was "inferentially" granted is somewhat inconsistent with his earlier position that the circuit court "retroactively" granted the extension.
¶ 28. The circuit court scheduled a contested hearing on the merits of the petition for the extension of the one-year dispositional order for December 3, 2002. The circuit court granted the State's motion after the December 3 hearing to extend Michael S.'s disposi-tional order for one year (until October 23, 2003) and changed his placement to Ethan Allen School.
¶ 29. The court of appeals affirmed the circuit court, holding that the requirements of Wis. Stat. § 938.365(6) had been fulfilled, because (1) a request was made for an extension of the one-year dispositional order before the expiration of the order; and (2) a hearing could not be held before the expiration of the one-year dispositional order. The court of appeals held [14]*14that Wis. Stat. § 938.365(6) does not require that a 30-day extension must be granted prior to the disposi-tional order's expiration, as long as the two conditions set forth above were met. Similarly, the court of appeals held that the circuit court is not required, under § 938.365(6), to explicitly inform the parties that it granted a temporary 30-day extension. Michael S. seeks review in this court. We reverse the decision of the court of appeals.
HH HH HH
¶ 30. The parties dispute whether the circuit court's failure to grant a temporary 30-day extension of Michael S.'s one-year dispositional order prior to October 23, 2002, the date of the expiration of the order, has any effect on the validity of the circuit court's order extending Michael S.'s dispositional order for an additional year and changing his placement to Ethan Allen School.
¶ 31. We turn to the relevant statutes and their application to the facts in the case at bar. Interpretation and application of statutes ordinarily present questions of law that this court decides independently of the circuit court and the court of appeals, benefiting from their analyses.5
¶ 32. The statutes at issue in the present case are Wis. Stat. §§ 938.34, 938.365(6), and 938.315(3).
¶ 33. Section 938.34 provides that when a juvenile is judged delinquent, a circuit court must enter an "order deciding one or more of the dispositions of the [15]*15case as provided in this section under a care and treatment plan."6 Dispositions under § 938.34 include counseling, supervision (intensive or otherwise), placement in a particular home, electronic monitoring, transfer of legal custody, institutional or correctional placement, aftercare supervision, restitution (in the form of money or services), work programs or community service, and various job, educational, drug or alcohol counseling programs.7 Pursuant to § 938.355(4)(a), the original dispositional order in the instant case provided that it would expire on October 23, 2002.
¶ 34. A circuit court may extend a dispositional order and change placement. Wisconsin Stat. § 938.365(6) allows a circuit court to extend a disposi-tional order for 30 days for the circuit court to hear a request to extend the dispositional order. Section 938.365(6) reads as follows:
If a request to extend a dispositional order is made prior to the termination of the order, but the court is unable to conduct a hearing on the request prior to the termination date [of the dispositional order], the court may extend the [dispositional] order for a period of not more than 30 days, not including any period of delay resulting from any of the circumstances specified in s. 938.315(1). The court shall grant appropriate relief as provided in s. 938.315(3) with respect to any request to extend a dispositional order on which a hearing is not held within the time limit specified in this subsection. Failure to object if a hearing is not held within the time limit specified in this subsection waives that time limit.
¶ 35. According to the text of Wis. Stat. § 938.365(6), if there is a request to extend a disposi-[16]*16tional order prior to the termination of the order, but the circuit court is unable to conduct a hearing on the request before the termination date of the dispositional order, the circuit court may extend the dispositional order for not more than 30 days. In the instant case, the State did request an extension of the dispositional order prior to the termination of the order. The circuit court was unable to conduct a hearing on the State's request before the termination date of the dispositional order. The circuit court did not, however, extend the disposition order for 30 days, probably because no request for a temporary extension under Wis. Stat. § 938.365(6) was made. The statute does not explicitly explain the consequences of a circuit court's failure to order a 30-day temporary extension of the dispositional order. The statute does provide that if a hearing is not held within the 30 days set forth in the temporary extension, failure to object waives that time limit.
¶ 36. The third relevant statute is Wis. Stat. § 938.315(3). This statute governs the failure to comply with any time limit specified in the Juvenile Justice Code (chapter 938). Section 938.315(3) provides that failure to comply with any time limit in chapter 938 does not deprive the court of personal or subject matter jurisdiction or of competency to exercise that jurisdiction and that failure to object to a delay or a continuance waives the time limit. Specifically, section 938.315(3) provides, in pertinent part, as follows:
Failure to comply with any time limit specified in this chapter does not deprive the court of personal or subject matter jurisdiction or of competency to exercise that jurisdiction. Failure to object to a period of delay or [17]*17a continuance waives the time limit that is the subject of the period of delay or continuance.8
[18]*18¶ 37. A request to extend the dispositional order and change placement, as we stated previously, was made in the present case in September 2002. The circuit court did not act upon the request prior to the expiration of the one-year dispositional order. No request was made for a temporary 30-day extension of the one-year dispo-sitional order under § 938.365(6) before the expiration of the one-year dispositional order.
[19]*19¶ 38. The dispositional order expired on October 23, 2002; the hearing on extending the order for another year was held on October 24, 2002.
¶ 39. The State argues that the circuit court inferentially granted the temporary 30-day extension on October 2, 2002, when it scheduled the hearing for October 24, and that no magic words are required for a circuit court to invoke a temporary 30-day extension of the dispositional order under Wis. Stat. § 938.365(6). The State asserts that the criteria for granting the temporary extension were met in the instant case: A request for an extension of a dispositional order was timely made, and the circuit court had difficulty scheduling the hearing earlier.
¶ 40. The State argues that the circuit court can extend a dispositional order by implication or inference or nunc pro tunc. We disagree with the State. A circuit court must follow the statutory procedure for extending an order.9 The statute does not allow for an extension by implication, by inference, or after the fact.
¶ 41. Particularly in juvenile proceedings, the juvenile and his or her relatives must be aware of the dispositional status of a juvenile; inferential orders do not comport with that notion, the statutes, or due process. The juvenile's liberty interests are at stake. To allow an extension by inference undermines all the certainty the legislature has attempted to build into chapter 938. As a one-year dispositional order nears its end, all the parties are aware that unless the state initiates additional action before the expiration date of the order, the circuit court's authority over the juvenile ceases.
[20]*20¶ 42. In the present case, if a 30-day temporary extension were granted by inference, no one would have been able to determine Michael S.'s status on October 23, 2003. It was only on October 24 that Judge Foley mentioned he was going to enter a temporary extension. Even then, the parties continued to dispute the court's authority to grant the order over at least three more hearings before two different judges. The goals of certainty and finality would not be achieved by inferential orders.
¶ 43. Section 938.365(6) allows a circuit court to "grant" an extension if certain conditions are present. Granting an extension is an affirmative act that advises all parties involved, as well as all the circuit court judges who act on the file.
¶ 44. While the circuit court is not required to utter "magic words" to extend a dispositional order temporarily for 30 days, it must enter a written or oral order of extension prior to the expiration of the underlying dispositional order. No order was entered in the instant case. The record does not reflect that the circuit court or the parties were aware that the contested hearing was set beyond the expiration of the one-year dispositional order. Had the circuit court entered on October 2 either a written or oral order granting a 30-day extension under Wis. Stat. § 938.365(6), this case would not be here.
¶ 45. Having rejected the State's position that the circuit court extended the dispositional order inferentially, by implication, or after the fact, prior to its expiration, we address now the parties' other arguments.
¶ 46. Relying on In re B.J.N., 162 Wis. 2d 635, 469 N.W.2d 845 (1991), in which the court stated that "[a] [21]*21dispositional order has no validity once the time period has elapsed,"10 Michael S. asserts that the circuit court lost both personal jurisdiction and competency over Michael S. once the one-year dispositional order expired on October 23. Michael S. contends that the circuit court was without authority to issue a temporary extension after the expiration date, and without the statutory 30-day temporary extension, argues Michael S., the circuit court was without authority to enter the subsequent one-year dispositional order.
¶ 47. In contrast, relying on Village of Trempealeau v. Mikrut11 and the statutes, the State argues that because Michael S. did not object to scheduling the hearing on October 24, he waived any challenge to the circuit court's ability to hear the State's request for an additional one-year dispositional order.
¶ 48. We now turn to Michael S.'s position B.J.N., upon which Michael S. relies, arose under chapter 48 of the Statutes (1987-88), the Children's Code, enacted in 1977. At the time B.J.N. was decided, chapter 48 set forth the requirements for dispositional orders for both juvenile delinquency and children in need of protection or services (CHIPS) cases.
¶ 49. Prior to the adoption of the Children's Code, the juvenile justice system allowed a dispositional order to last until the juvenile's eighteenth birthday. There was no statutorily required expiration date of a dispo-sitional order before the juvenile attained the age of [22]*2218.12 This lack of an expiration date for a dispositional order "often resulted in an abuse of detention."13
¶ 50. As revised in 1979, the Children's Code empowered circuit courts to issue juvenile dispositional orders for a one-year period and, if the order was to be extended, required circuit courts to hold formal hearings on whether to extend a dispositional order.14 The Children's Code thus afforded a juvenile an annual review15 and did not allow a "gap" between the expiration date of the dispositional order and the date on which a new order was entered.16
¶ 51. The primary function of the expiration date of a dispositional order was to ensure the protection of a juvenile's due process rights.17 Indeed, "some of the more important revisions of ch. 48 [were] made in the 1970's in order to implement major United State Supreme Court decisions and assure the constitutional rights of children. . . ,"18 The Children's Code recognized that a juvenile has a constitutionally protected liberty interest and should be subject to a dispositional [23]*23order only if one is needed.19 The Children's Code's new temporal limitations were designed to protect the juvenile's constitutional liberty interest. A juvenile has a due process right to have his or her disposition re-determined by a fixed date.20
¶ 52. With this background about the Children's Code, we turn to B.J.N. In B.J.N., unlike in the present case, the circuit court granted a temporary 30-day extension of a one-year dispositional order before the order expired. No hearing was held, however, during the 30-day period. The question was whether under Wis. Stat. § 48.365(6) (1987-88),21 the predecessor to Wis. Stat. § 938.365(6), the one-year dispositional order [24]*24could be extended beyond 30 days and whether Wis. Stat. § 48.315 (1987-88),22 a predecessor to Wis. Stat. [25]*25§ 938.315, could be used to expand the duration of a 30-day extension of a dispositional order.23
¶ 53. The B.J.N. court held that the circuit court lost its competence to exercise jurisdiction when the hearing was not held within the 30-day time period under Wis. Stat. § 48.365(6) (1987-88); that § 48.315 (1987-88) could not be used to enlarge the 30-day time period of the dispositional order; and that the parties could not waive the circuit court's loss of competency after the 30-day extension terminated.
¶ 54. Resting its decision on the text of the statutory provisions and the objectives of the drafters of the Children's Code, the B.J.N. court concluded that "[a] dispositional order has no validity once the time period has elapsed"24 unless a temporary extension was granted before the expiration of the one-year disposi-tional order.
¶ 55. The B.J.N. court concluded that a juvenile cannot waive the right to challenge the scheduling of a post-dispositional proceeding after the expiration of the 30-day extension.25 The B.J.N. court highlighted that the court has "consistently ruled that a court's loss of [26]*26power due to the failure to act within statutory time periods cannot be stipulated to nor waived."26 "An objecting party's failure to expressly raise the loss of competence at the earliest available moment cannot revive an order which has expired and no longer carries any force of law."27
¶ 56. With regard to the application of Wis. Stat. § 48.315 (1987-88), the B.J.N. court held that § 48.315 (1987-88) did not apply to extensions of dispositional orders. Section 48.315(1) (1987-88) provided that certain enumerated periods of delay or continuance "shall be excluded in computing time requirements within this chapter." The B.J.N. court concluded that "the length of time a dispositional order can remain in effect... is not really a 'requirement' or 'deadline' by which time something must be done to proceed to the next step."28 The 30-day extension under § 48.365(6) (1987-88) represents the length of time an order stays in effect, according to the B.J.N. court. Thus the court ruled in B.J.N. that § 48.315 (1987-88) did not allow the dispositional order to remain in effect beyond its stated expiration date.
¶ 57. To determine the applicability of B.J.N. to the present case, we have to compare the Children's Code to the Juvenile Justice Code, which governs the present case. In 1995, the legislature created chapter 938, the Juvenile Justice Code, which governs delinquent juveniles; CHIPS cases remain in chapter 48.29 The 1995 Juvenile Justice Code revised sections of the Children's Code applicable to delinquent juveniles. Rel[27]*27evant to this case are changes from Wis. Stat. §§ 48.365(6) and 48.315 (1987-88) in §§ 938.365(6) and 938.315.
¶ 58. The text of Wis. Stat. § 938.365(6) regarding the request for a 30-day temporary extension of the dispositional order is essentially unchanged from the text of Wis. Stat. § 48.365(6) (1987-88) interpreted in B.J.N., except for the addition of the sentence stating that "[failure to object if a hearing is not held within the time limit specified in this subsection waives that time limit."
¶ 59. This final sentence of Wis. Stat. § 938.365(6) does not apply in the present case because this sentence is obviously tied to the preceding sentences, which relate to a request made prior to expiration of the order to extend a dispositional order for 30 days in order to hold a hearing. That is, the "time limit" referred to is holding the hearing within 30 days. In the present case no request for a 30-day extension of the dispositional order was made and none was granted before the expiration of the order. Accordingly, the waiver provision of § 938.365(6) is inapplicable here, and under B.J.N., the one-year dispositional order in the present case had no validity once its expiration date, October 23, was reached.
¶ 60. We turn now to a new provision in the Juvenile Justice Code, Wis. Stat. § 938.315(3), upon which the State relies for the proposition that failure to comply with the 30-day provision in Wis. Stat. § 938.365(6) does not deprive the circuit court of personal or subject matter jurisdiction or competency and [28]*28that Michael S.'s failure to object to the delay waived the time limit. Section 938.315(3) reads in relevant part as follows:
Failure to comply with any time limit specified in this chapter does not deprive the court of personal or subject matter jurisdiction or of competency to exercise that jurisdiction. Failure to object to a period of delay or a continuance waives the time limit that is the subject of the period of delay or continuance.
¶ 61. The State's argument is not persuasive. It is answered by the B.J.N. decision. The expiration date of a dispositional order is not a "time limit" contemplated in Wis. Stat. § 938.315(3). The B.J.N court explained this conclusion, stating, "The length of time a disposi-tional order can remain in effect, however, is not really a 'requirement' or 'deadline' by which something must be done to proceed to the next step."30 Accordingly, we conclude that § 938.315(3) does not apply in the present case to extend the one-year dispositional order.
¶ 62. When the legislature wanted to use the term "time limits" in chapter 938 with reference to specifically enumerated periods, it did so.31 The fundamental difference between a "time limit" as described in Wis. [29]*29Stat. § 938.315(3) and the expiration of the one-year dispositional order is as follows: "Time limits" are those constraints that require action within a set period of time. In contrast, when a one-year dispositional order expires, it simply ceases to be in effect. Unless an order is entered extending the one-year dispositional order before the dispositional order expires, nothing in §§ 938.315(3) or 938.365(6) extends the validity of the one-year dispositional order.
¶ 63. The difference between "time limits" and the durational period of dispositional orders was retained by the court of appeals in In re Sarah R.P., a recent court of appeals decision relating to Wis. Stat. § 938.32, which governs consent decrees.32
¶ 64. In Sarah R.P., a circuit court attempted to vacate a consent decree entered under chapter 938. The consent decree in the delinquency action included a curfew and a condition that Sarah R.E not engage in further law violations. The consent decree at issue was to remain in effect until December 8. The State filed a petition to vacate the decree on December 1, alleging that Sarah R.E violated the curfew and stole two pens from school. The hearing on the State's petition was not held until December 21, 13 days after the consent decree expired. No temporary extension of the consent decree was requested or entered.
¶ 65. The circuit court accepted the State's contention that the provisions of Wis. Stat. § 938.315 allowed for an extension of the consent decree after the [30]*30expiration date of the decree and entered a dispositional order. Sarah R.E challenged the order in the court of appeals.
¶ 66. The court of appeals reversed the circuit court, concluding that the durational period of a consent decree is not a time limit within Wis. Stat. § 938.315 but rather provided for a "period of supervision" that terminated at the conclusion of the period set forth in the decree.33 According to Sarah R.P., once "the decree has expired, it cannot be resurrected."34
¶ 67. The court of appeals also rejected the State's argument that Sarah R.E waived the right to challenge the expiration of the decree by not raising it at or before the December 21 hearing.35
¶ 68. Applying the principles derived from B.J.N. and Sarah R.P., we would have to conclude that the circuit court had no authority over the Michael S. matter after the one-year dispositional order expired on October 23.
¶ 69. We now turn to the State's position to determine whether the Mikrut case undermines our reliance on B.J.N. and Sarah R.E for the proposition that when no order is in effect extending the dispositional order, the circuit court has no authority over the juvenile.
¶ 70. The State relies on Village of Trempealeau v. Mikrut, 2004 WI 79, ¶¶ 27-30, 273 Wis. 2d 76, 681 N.W.2d 190, to assert that Michael S. waived his right to challenge on appeal the circuit court's loss of competency when he failed to challenge the scheduling of the contested hearing for October 24, 2002, at the October [31]*312 hearing. The State relies on Mikrut for the proposition that a challenge to a circuit court's competency is waived if not raised in the circuit court.
¶ 71. Mikrut was issued 21 citations for violations of local ordinances.36 He was found guilty, appealed, and lost, and this court denied his petition for review.37 Mikrut then moved, 17 months after the guilty verdict, to vacate the judgment.38 Mikrut claimed the citations were illegal because the village failed to comply with statutory mandates in issuing the citations.39 The Mik-rut court held that competency does not equate to subject matter jurisdiction and that a challenge to the circuit court's competency is waived if not raised in the circuit court.40 The Mikrut court, however, backed off from adopting a categorical rule that all competency objections must be made at the circuit court or be waived.41 For example, the court held open the question whether statutory time periods can be waived.42
¶ 72. The State agrees that Mikrut left open the question whether a challenge to competency based on noncompliance with a statutory time period can be waived. The court explained in Mikrut, for example, that in "the failure to timely hold a hearing on a
request for an extension of a CHIPS order under Wis. Stat. § 48.365(2) resulted in a loss of the circuit court's competency to proceed, because without the statutorily-required hearing on the extension, the original order [32]*32expired."43 Mikrut summarized B.J.N. as acknowledging that" 'we have consistently ruled that a court's loss of power due to the failure to act within statutory time periods cannot be stipulated to nor waived.' "44
¶ 73. Thus the waiver rule of Mikrut does not, according to Mikrut, control the outcome of this case. The present case involves a statutory time period that Mikrut left undisturbed.
¶ 74. The State provides no persuasive reason to extend Mikrut and overrule B.J.N.'s holding that "[a] dispositional order has no validity once the time period has elapsed."45 We therefore abide by Mikrut and B.J.N.46
* * * *
¶ 75. For the foregoing reasons, we hold that after a juvenile's one-year dispositional order expires, a circuit court may not grant a 30-day temporary extension of the order under Wis. Stat. § 938.365(6). Further, [33]*33consistent with caselaw, expiration of the one-year juvenile dispositional order cannot be waived. Because no 30-day temporary extension was granted prior to the expiration of the one-year dispositional order, the circuit court could not act with respect to Michael S. once the one-year dispositional order expired.
¶ 76. By the Court. — The decision of the court of appeals is reversed.