Subject to subsection (2) below, where the amount of a penalty is to be ascertained by reference to tax payable by a person for any period, the penalty may be determined by an officer of the Board, or proceedings for the penalty may be commenced before the tribunal or a Court—
at any time within six years after the date on which the penalty was incurred, or
at any later time within three years after the final determination of the amount of tax by reference to which the amount of the penalty is to be ascertained.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A penalty to which subsection (1) does not apply may be so determined, or proceedings for such a penalty may be commenced before the tribunal or a court, at any time within six years after the date on which the penalty was incurred or began to be incurred.