N.Y. Gen. Constr. Law § 25-a

§ 25-a. Public holiday, Saturday or Sunday in statutes; extension of\ntime where performance of act is due on Saturday, Sunday or public\nholiday. 1. When any period of time, computed from a certain day, within\nwhich or after which or before which an act is authorized or required to\nbe done, ends on a Saturday, Sunday or a public holiday, such act may be\ndone on the next succeeding business day and if the period ends at a\nspecified hour, such act may be done at or before the same hour of such\nnext succeeding business day, except that where a period of time\nspecified by contract ends on a Saturday, Sunday or a public holiday,\nthe extension of such period is governed by section twenty-five of this\nchapter.\n 2. Where time is extended by virtue of the provisions of this section,\nsuch extended time shall not be included in the computation of interest,\nexcept that when the period is specified as a number of months, such\nextended time shall be included in the computation of interest.\n