(8) of section 139 provided: "Where the return under sub section (1) or sub section (2) or sub section (4) for an assessment year is furnished after the 30th day of September of the assessment year, or is not furnished, then (whether or not the Income tax Officer has extended the date for furnishing the return under sub section (1) or sub section (2), the assessee shall be liable to pay simple interest at nine per cent per annum, reckoned from the 1st day of October of the assessment year to the date of the furnishing of the return or, where no return has been furnished, the date of completion of the assessment under section 144, on the amount of the tax payable on the total income as determined on regular assessment, as reduced by the advance tax, if any, paid and any tax deducted at source: Provided that in the case of any person whose total income includes any income from business or profession, the previous year in respect of which expired after the 31st day of December of the year immediately preceding the asessment year, such interest shall be reckoned from the 1st day of January instead of 1st day of October of the assessment year: 145 Provided further that the Income tax Officer may, in such cases and under such circumstances as may be prescribed, reduce or waive the interest payable by any person under this sub section.