Tax Law, §§ 651, 652

The New York State income tax returns of individuals, trusts, estates or partnerships required to be made under this Subchapter must be filed on or before the 15th day of the fourth month following the close of the taxable year (April 15th in the case of a calendar year taxpayer). The words close of the taxable year referred to in the previous sentence have the same meaning for New York State income tax purposes as when used for Federal income tax purposes. See section 152.11 of this Part for the time for filing a New York State personal income tax return of a nonresident alien individual and section 158.9 of this Article for the time for filing a New York State partnership return where the partnership consists entirely of nonresident aliens.