(1)Where a patient who is liable to be detained in a hospital under this Part of this Act is detained in custody in pursuance of any sentence or order passed or made by a court in the United Kingdom (including an order committing or remanding him in custody) and is so detained for a period exceeding 6 months, he shall, at the end of that period, cease to be so liable.
(2)Where any such patient is detained in custody as aforesaid for a period not exceeding 6 months, or for successive periods that do not in the aggregate exceed 6 months, then—
(a)if apart from this subsection the patient would have ceased to be liable to be detained as aforesaid on or before the day he is discharged from custody, he shall not cease to be so liable until the end of that day ; and
(b)in any case, sections 28 and 31 of this Act shall apply in relation to the patient as if he had absented himself without leave on that day.