515. (1) The period of limitation, in relation to an offender, shall commence,—
(a) on the date of the offence; or
(b) where the commission of the offence was not known to the person aggrieved by the offence or to any police officer, the first day on which such offence comes to the knowledge of such person or to any police officer, whichever is earlier; or
(c) where it is not known by whom the offence was committed, the first day on which the identity of the offender is known to the person aggrieved by the offence or to the police officer making investigation into the offence, whichever is earlier.
(2) In computing the said period, the day from which such period is to be computed shall be excluded.