In Andrea L. v. Superior Court (1998) 64 Cal.App.4th 1377, 1388, the Court of Appeal found that the juvenile court did not abuse its discretion in refusing to extend services beyond the 18-month statutory limit where the mother received reasonable services and the failure of the case plan was due to the mother's relapse into substance abuse. ( Id. at pp. 1388-1389.) In Andrea L. v. Superior Court (1998) 64 Cal.App.4th 1377, the denial of a contested 18-month hearing. There, a mother sought writ review of a juvenile court's order terminating family reunification services to three minors, Chavonne, Larry and Joshua. ( Id. at p. 1379.) The juvenile court in February 1997 ordered the mother to submit to individual counseling, domestic abuse counseling, parenting instruction, and drug counseling including random drug testing. In April 1997 DCFS could not verify the mother's participation in a drug program. The mother admitted that she had not enrolled in a domestic violation class or individual counseling. Her visitation was sporadic. A case plan update indicated that the mother subsequently enrolled in parenting, drug counseling and individual counseling. ( Id. at p. 1381.) A subsequent DCFS family assessment update prepared for the permanency planning hearing reported that while the mother tested positive for cocaine metabolite on January 15, 1998, she tested negative on January 27, February 5, 11 and 20. A March 3, 1998 report from the mother's residential drug treatment program indicated that the mother had made "'great changes in her decision making skills, communication skills and had a much more positive outlook. . . .' However, based on mother's positive test result, mother had been reinstated for an additional four months 'to make sure that this situation remains isolated and that we solve the initial problem which has caused mother to relapse.'" ( Id. at p. 1382.) At the 18-month permanency planning hearing in Andrea L., the mother requested a contested hearing over DCFS's recommendation to terminate family reunification services. The juvenile court responded by asking for an offer of proof. The mother's attorney replied that she would testify that except for the one positive test result, the mother "'has been in complete and total compliance with the case plan, including a full program. Her testing before that and after that has been negative. She continues to test. She is now employed.'" (64 Cal.App.4th at pp. 1382-1383.) Noting that it was at the 18-month date, the juvenile court concluded: "'I don't think mother's offer of proof is sufficient. . . . I think that one dirty test just shows me that all that counseling, all that work didn't take hold, and maybe now it will. And if it does, then she can file a petition for modification under section 388. . . .'" ( Id. at p. 1384.) The mother's attorney subsequently requested a four-month extension of family reunification services to allow the mother to complete the residential drug treatment program. The juvenile court denied the request, stating "'mother has had 18 months.'" (Ibid.) The mother then pleaded for "'another chance.' The juvenile court responded, 'the law doesn't give me a whole lot of outs right here, and the 18 months have passed.' 'Mother had made progress, and then, as she says, made this terrible mistake, but it's a very costly mistake. If she continues to test clean, continues the Toberman House residential drug treatment program, she can file a section 388 petition, and the Court would certainly consider it. The Court believes at this point because it is the 18-month date and I do not have any extraordinary circumstances . . . that precluded the mother from obeying the orders of the Court, family reunification services must be terminated. Even if the Court were to allow a full hearing . . ., the evidence that would be presented still does not outweigh the concern the Court has for the welfare of these children because of that dirty test and mother's relapse. I just would need much more time, because there's no way I would return these children today, and I need more time for her clean tests, more time for her, for more letters from Toberman, and she can certainly file those with the section 388 petition.'" ( Id. at pp. 1384-1385.) Concluding that the juvenile court erred in denying the requested contested hearing on DCFS's recommendation to terminate family reunification services, the appellate court examined the record to determine whether the error was prejudicial. ( Andrea L. v. Superior Court, supra, 64 Cal.App.4th at pp. 1386-1387.) It was noted that the DCFS reports showed the mother's "relapse into cocaine abuse and her failure to test on other dates around January 15, 1998. These facts were uncontested and mother's counsel did not request an opportunity to cross-examine the author of the reports. Indeed, mother admitted in her statement to the juvenile court that she had made a mistake. Additionally, the juvenile court accepted as true counsel's representation that mother and her counselor would testify mother's relapse had been an isolated incident, the duration and the quality of the relapse had to be considered, mother remained motivated and involved in the Toberman Settlement House program, mother's counselor had confidence in mother's ability to complete the program successfully, and mother's counselor recommended that mother be provided further family reunification services. Although the juvenile court accepted every aspect of mother's offer of proof, it nonetheless concluded the minors could not be returned to mother because her relapse had been too recent." (64 Cal.App.4th at pp. 1386-1387.) The appellate court determined that "the juvenile court did not mistakenly believe mother's right to a contested hearing previously had been satisfied. Rather, it implicitly conceded mother was entitled to contest the sufficiency of the evidence contained in the social reports and to produce evidence on her own behalf. However, after inquiring what proof mother would adduce at such a hearing, the juvenile court concluded mother's showing would be insufficient to warrant either return of the minors to mother or an extension of family reunification services. Because the juvenile court accepted mother's offer of proof as true, and mother did not seek to cross-examine the author of the social studies before the juvenile court, the present record permits us to determine whether mother was prejudiced by the juvenile court's denial of the request for a contested hearing." ( Id. at p. 1387.) The Andrea L. appellate court concluded that on the record, "beyond a reasonable doubt, no different result would have obtained had mother's request for a contested hearing been granted. Accordingly, even under the most stringent test of prejudice applicable to a denial of due process, remand for a contested hearing would constitute an idle act and the juvenile court's error must be seen as harmless beyond a reasonable doubt. " (64 Cal.App.4th at p. 1387.) The Andrea L. court next rejected the mother's contention that the juvenile court should have extended family reunification services. (64 Cal.App.4th at p. 1388.) "The Legislature has recognized there must be a limitation on the length of time a child has to wait for a parent to become adequate in order to prevent children from spending their lives in the uncertainty of foster care. Thus, family reunification services 'may be extended up to a maximum time period not to exceed 18 months if it can be shown that the objectives of the service plan can be achieved within the extended time period.' ( 361.5, subd. (a)(2).) The reunification period is expressly not tolled by a parent's absence. . . . ( 361.5, subd. (e)(1).)" ( Id. at p. 1388.) While a juvenile court may exercise its discretion to extend reunification services beyond the statutory limit in "special needs" cases, those cases involve "extraordinary circumstances which militated in favor of extension of family reunification services beyond the 18-month limit. These circumstances uniformly involved some external factor which prevented the parent from participating in the case plan" such as a parent's hospitalization during a critical state of the reunification period or where reunification services were inadequate. ( Andrea L. v. Superior Court, supra, 64 Cal.App.4th at p. 1388.) "In this case, mother received reasonable family reunification services. Mother does not contend otherwise. The failure of the case plan was not caused by inadequate services or an external force over which mother had no control, but by mother's relapse into cocaine abuse. The juvenile court reasonably could conclude such a relapse does not constitute the extraordinary circumstances or special needs necessary to support an extension of family reunification services beyond the statutory limit. Accordingly, the juvenile court committed no error in refusing to extend family reunification services in this case." ( Id. at p. 1389.) It is clear that the court committed a procedural error under California Rules of Court, rule 1463(a) when it terminated mother's rights in a hearing separate from the hearing in which the father's rights were terminated. However, father's parental rights were terminated five months later and so now the rights of both parents have been severed and the child is free for adoption. Moreover, mother has not challenged the termination of her parental rights on any substantive ground and father abandoned his appeal . Therefore, we conclude with certainty, even under the most stringent test of prejudice applicable, that no different result would have obtained had the court continued mother's section 366.26 hearing until father had received adequate notice. Accordingly, remand for another hearing would constitute an idle act; and the law does not require idle acts. (See Civ. Code, 3532; see Andrea L. v. Superior Court (1998) 64 Cal. App. 4th 1377, 1387 75 Cal. Rptr. 2d 851)