N.Y. Comp. Codes R. & Regs. tit. 20, § 535.1
(c) Any period of time provided by this Part which begins by the giving of notice commences to run from the date of mailing of such notice.
Cross-reference:
For rules applicable to the mailing of documents by taxpayers, see Part 2399 of this Title.
Tax Law, § 1147(a)