(1)In section 9 of the [1967 c. 80.] Criminal Justice Act 1967 (proof by written statement) in subsection (3)(a) (statement by person under 21 must give his age) for “twenty-one” there shall be substituted “eighteen”.
(2)This section applies in relation to statements tendered in evidence on or after the appointed day.
(3)The reference in subsection (2) to the appointed day is to such day as is appointed for the purposes of this section by the Secretary of State by order.