A provision contained in any of sections 6, 12 to 17, 26, 28, 29, 31, 36, 40 to 42 and 46(1)(b) of, and Schedules 1 and 4 to, this Act and any related amendment or repeal provided for in Schedule 7 or 8 to this Act, shall not apply in relation to proceedings which have been instituted before the coming into force of that provision; and, for the purposes of this paragraph, proceedings shall be taken to have been instituted on the day on which the petition or complaint is served on the accused.