The trial of a person for an offence (other than a sexual offence) must commence—
(a) within 12 months after the day on which the person is committed for trial in respect of the offence; or
(b) if no committal proceeding in respect of the offence is held, within 12 months after the day on which the indictment against the person is filed; or
(c) if a new trial is ordered by the Court of Appeal, within 6 months after the day on which the order is made; or
(d) if the period referred to in paragraph (a), (b) or (c) or any extension of that period is extended under section 247, within the extended period.