This section applies where a patient who is absent without leave is taken into custody under section 18 above, or returns himself to the hospital or place where he ought to be, not later than the end of the period of 28 days beginning with the first day of his absence without leave.

Where the period for which the patient is liable to be detained or subject to guardianship is extended by section 21 above, any examination and report to be made and furnished in respect of the patient under section 20(3) or (6) above may be made and furnished within the period as so extended.

Where the authority for the detention or guardianship of the patient is renewed by virtue of subsection (2) above after the day on which (apart from section 21 above) that authority would have expired, the renewal shall take effect as from that day.

In the case of a community patient, where the period for which the community treatment order is in force is extended by section 21 above, any examination and report to be made and furnished in respect of the patient under section 20A(4) above may be made and furnished within the period as so extended.

Where the community treatment period is extended by virtue of subsection (4) above after the day on which (apart from section 21 above) the order would have ceased to be in force, the extension shall take effect as from that day.