--(a) Assessment date.--The amount of tax which a return shows to be due, or the amount of tax which a return would have shown to be due but for a mathematical error, shall be deemed to be assessed on the date of filing of the return (including any amended return showing an increase of tax). In the case of a return properly filed without computation of tax, the tax computed by the administrator shall be deemed to be assessed on the date on which payment is due. If a notice of deficiency has been mailed, the amount of the deficiency shall be deemed to be assessed on the date specified in subdivision (b) of section sixty-one if no petition to the administrator is filed, or if a petition is filed, then upon the date when a decision of the administrator establishing the amount of the deficiency becomes final. If an amended return or report filed pursuant to section thirty-nine concedes the accuracy of a federal adjustment, change or correction, any deficiency in tax under this local law resulting therefrom shall be deemed to be assessed on the date of filing such report or amended return, and such assessment shall be timely notwithstanding section sixty-three. If a notice of additional tax due, as prescribed in subdivision (e) of section sixty-one, has been mailed, the amount of the deficiency shall be deemed to be assessed on the date specified in such subdivision unless within thirty days after the mailing of such notice a report of the federal change or correction or an amended return, where such return was required by section thirty-nine, is filed accompanied by a statement showing wherein such federal determination and such notice of additional tax due are erroneous. Any amount paid as a tax or in respect of a tax, other than amounts withheld at the source or paid as estimated income tax, shall be deemed to be assessed upon the date of receipt of payment, notwithstanding any other provisions.

1. (b) Other assessment powers.--If the mode or time for the assessment of any tax under this local law (including interest, additions to tax and assessable penalties) is not otherwise provided for, the administrator may establish the same by regulations.
2. (c) Estimated income tax.--No unpaid amount of estimated tax under section thirty-six shall be assessed.
3. (d) Supplemental assessment.--The administrator may, at any time within the period prescribed for assessment, make a supplemental assessment, subject to the provisions of section sixty-one where applicable, whenever it is ascertained that any assessment is imperfect or incomplete in any material respect.
4. (e) Cross reference.--For assessment in case of jeopardy, see section seventy-four.