(a) When a youth is placed pursuant to a delinquency adjudication pursuant to article 3 of the Family Court Act with a local social services district, the commissioner or an authorized representative shall calculate the length of placement, consistent with the family court order initially placing the juvenile delinquent. Such calculation shall include a credit for time spent in detention, unless the family court denies all or part of such credit pursuant to section 353.3(5) or 353.5(5)(a)(i) of the Family Court Act.

(b) In the event a youth placed pursuant to a delinquency adjudication is absent without consent, pursuant to section 431.8 of this Part, the placement shall be interrupted and tolled by the absence, consistent with the provision of section 431.20 of this Part.