A reference to an offence in any of the following sections includes an offence committed before the commencement of the section:
(a) section 84 (Reporting period—single class 1 offence—15 years);
(b) section 85 (Reporting period—single class 2 offence—8 years);
(c) section 86 (Reporting period—2 class 2 offences—15 years);
(d) section 87 (Reporting period—multiple offences—life).