(a) A client 18 years of age or over, who is not under guardianship, shall be allowed to be discharged from the facility at the earliest appropriate time, not to exceed 5 days, excluding Saturdays, Sundays and holidays, after he submits a written objection to the facility director, unless he either withdraws the objection in writing or unless within the 5 day period a petition and certificate conforming to the requirements of Section 4-501 are filed with the court. Upon receipt of the petition, the court shall order a hearing to be held within 5 days, excluding Saturdays, Sundays and holidays, and to be conducted pursuant to Article VI of this Chapter. Admission of the client may continue pending further order of the court. In all other objections to admission under this Article, paragraph (b) of this Section and Sections 4-307 and 4-308 shall apply.(b) Unless the objection is withdrawn in writing or the client is discharged, the facility director shall file a petition for review of the admission with the court within 5 days of submission of the objection, excluding Saturdays, Sundays and holidays as provided in Sections 4-307 and 4-308. The facility director shall also file the report of the client's diagnostic evaluation and current habilitation plan with the court.