(a) General rule.--The time within which a matter must be commenced under this chapter shall be computed, except as otherwise provided by subsection (b) or by any other provision of this chapter, from the time the cause of action accrued, the criminal offense was committed or the right of appeal arose.
(b) Implementing court rules.--Subsection (a) may be made more specifically applicable to particular classes of matters by general rules defining the acts, omissions or events from which the limitation shall be computed. Rules adopted pursuant to this section shall take effect only in the manner provided by section 503(b) (relating to procedures).