A. When a child is held continuously in secure detention, he shall be released from confinement if there is no adjudicatory or transfer hearing conducted by the court for the matters upon which he was detained within twenty-one days from the date he was first detained.
B. If a child is not held in secure detention or is released from same after having been confined, an adjudicatory or transfer hearing on the matters charged in the petition or petitions issued against him shall be conducted within 120 days from the date the petition or petitions are filed.
C. When a child is held in secure detention after the completion of his adjudicatory hearing or is detained when the juvenile court has retained jurisdiction as a result of a transfer hearing, he shall be released from such detention if the disposition hearing is not completed within thirty days from the date of the adjudicatory or transfer hearing.
D. The time limitations provided for in this section shall be tolled during any period in which (i) the whereabouts of the child are unknown, (ii) the child has escaped from custody, (iii) the child has failed to appear pursuant to a court order, or (iv) a report is being prepared pursuant to the written request by the attorney for the Commonwealth in accordance with subsection C of § 16.1-269.1. The limitations also may be extended by the court for a reasonable period of time based upon good cause shown, provided that the basis for such extension is recorded in writing and filed among the papers of the proceedings. For the purposes of this section, good cause includes extension of limitations necessary to obtain the presence of a witness to testify regarding the results of scientific analyses or examinations and good cause shown by the director of the court services unit completing a report pursuant to subsection C of § 16.1-269.1 that additional time is needed for the completion of the report.