“deferred interest” includes –

 

(a)     any interest where such interest (or any portion thereof), calculated in respect of any accrual period falling within the term of any instrument by applying a constant interest rate throughout the term of such instrument, is not payable or receivable in terms of such instrument within one year from the date of the commencement of such accrual period; and

 

(b)     any interest payable or receivable in terms ol any instrument where such interest is not calculated by applying a constant interest rate throughout the term of such instrument;