This Act shall come into force on such day as the Secretary of State may appoint by order made by statutory instrument, and different days may be appointed for different provisions or different purposes.

Nothing in a provision of this Act applies in relation to an offence committed or act done before the provision comes into force.

Where a provision of this Act comes into force for certain purposes only, the references in subsection (2) to the provision are references to it so far as it relates to those purposes.