British Nationality Act 1981

9(1)For the purposes of this Schedule a person shall (subject to paragraph 2(b)) be treated as having been absent from the United Kingdom during any of the following periods, that is to say—U.K.

(a)any period when he was in the United Kingdom and either was entitled to an exemption under section 8(3) or (4) of the M1Immigration Act 1971 (exemptions for diplomatic agents etc. and members of the forces) or was a member of the family and formed part of the household of a person so entitled;

(b)any period when he was detained—

(i)in any place of detention in the United Kingdom in pursuance of a sentence passed on him by a court in the United Kingdom or elsewhere for any offence;

(ii)in any hospital in the United Kingdom under a hospital order made under [F1Part III of the Mental Health Act 1983] or section 175 or 376 of the M2Criminal Procedure (Scotland) Act 1975 or Part III of the Mental Health [F2(Northern Ireland) Order 1986], being an order made in connection with his conviction of an offence; or

(iii)under any power of detention conferred by the immigration laws of the United Kingdom;

(c)any period when, being liable to be detained as mentioned in paragraph (b)(i) or (ii) of this sub-paragraph, he was unlawfully at large or absent without leave and for that reason liable to be arrested or taken into custody;

(d)any period when, his actual detention under any such power as is mentioned in paragraph (b)(iii) of this sub-paragraph being required or specifically authorised, he was unlawfully at large and for that reason liable to be arrested.

(2)For the purposes of this Schedule a person shall (subject to paragraph 6(b)) be treated as having been absent from any particular [F3British overseas territory] during any of the following periods, that is to say—

(a)any period when he was in that territory and either was entitled to an exemption under the immigration laws of that territory corresponding to any such exemption as is mentioned in sub-paragraph (1)(a) or was a member of the family and formed part of the household of a person so entitled;

(b)any period when he was detained—

(i)in any place of detention in the relevant territory in pursuance of a sentence passed on him by a court in that territory or elsewhere for any offence;

(ii)in any hospital in that territory under a direction (however described) made under any law for purposes similar to , [F4Part III of the Mental Health Act 1983] which was for the time being in force in that territory, being a direction made in connection with his conviction of an offence and corresponding to a hospital order under that Part; or

(iii)under any power of detention conferred by the immigration laws of that territory;

(c)any period when, being liable to be detained as mentioned in paragraph (b)(i) or (ii) of this sub-paragraph, he was unlawfully at large or absent without leave and for that reason liable to be arrested or taken into custody;

(d)any period when, his actual detention under any such power as is mentioned in paragraph (b)(iii) of this sub-paragraph being required or specifically authorised, he was unlawfully at large and for that reason liable to be arrested.