§ 139. Mailing rules; holidays. (a) Timely mailing.--If any claim,
statement, notice, petition, or other document (including to the extent
authorized by the director of finance, a return or a declaration of
estimated tax) required to be filed within a prescribed period or on or
before a prescribed date under authority of any provision of this title
is, after such period or such date, delivered by the United States mail
to the director of finance, bureau, office, officer or person with which
or with whom such document is required to be filed, the date of the
United States postmark stamped on the envelope shall be deemed to be the
date of delivery. This subdivision shall apply only if the postmark
date falls within the prescribed period or on or before the prescribed
date for the filing of such document, determine with regard to any
extension granted for such filing, and only if such document was
deposited in the mail, postage prepaid, properly addressed to the
director of finance, bureau, office, officer or person with which or
with whom the document is required to be filed. If any document is sent
by United States registered mail, such registration shall be prima facie
evidence that such document was delivered to the director of finance,
bureau, office, officer or person to which or to whom addressed. To the
extent that the director of finance shall prescribe by regulation,
certified mail may be used in lieu of registered mail under this
section. This subdivision shall apply in the case of postmarks not made
by the United States Post Office only if and to the extent provided by
regulations of the director of finance.

(b) Last known address.--For purposes of this title, a taxpayer's last
known address shall be the address given in the last return filed by
him, unless subsequently to the filing of such return the taxpayer shall
have notified the director of finance of a change of address.

(c) Last day a Saturday, Sunday or legal holiday.--When the last day
prescribed under authority of this title (including any extension of
time) for performing any act falls on Saturday, Sunday, or a legal
holiday in the state of New York, the performance of such act shall be
considered timely if it is performed on the next succeeding day which is
not a Saturday, Sunday or a legal holiday.