(1) Subject to subsection (2), an interim detention order commences—
(a) if the offender is serving a custodial sentence when the interim detention order is made, on the day on which the offender completes the custodial sentence or any consecutive or concurrent custodial sentence, whichever is the later; or
(b) if the offender is remanded in custody when the interim detention order is made, on the day on which the offender is released from custody; or
(c) if the offender is in immigration detention when the interim detention order is made, on the day on which the offender is released from immigration detention; or
(d) in any other case, on the date specified in the interim detention order.
(2) If an offender is the subject of an application for the renewal of a detention order, an interim detention order commences—
(a) on the expiry of the previous detention order, if still in force; or
(b) on the date specified in the interim detention order.