Interest deduction timing revised: allowed within a prescribed period and conditional on lender certificate specifying interest for acquisition. Section 24(b) is amended to replace the prior deadline with a three-year time limit measured from the end of the financial year in which capital was borrowed, and to add a proviso requiring an assessee to furnish a certificate from the interest-payee specifying interest payable for acquisition or construction or for conversion of capital into a new loan; 'new loan' is defined as any subsequent loan or part thereof taken to repay the original capital.