N.Y. Town Law § 244
When it shall be ascertained to the satisfaction of the said board that any error, omission or mistake has been made in measuring or in entering the frontage or bounds of any lot or in the quantity of any parcel of land held to be especially benefited by an improvement or in any other matter connected with the making of a local assessment, it shall be lawful for the said board, and it is hereby authorized to correct such error, omission or mistake. Before making any such correction, however, it shall give to the owner or occupant of the land against which an assessment is to be made or increased, notice personally, or by mail, specifying a time, which shall be at least five days after the mailing or service of the notice, and a place at which the said board will meet for the purpose of correcting such alleged error, omission, or mistake, and shall give to such person at such time and place an opportunity to be heard, and to make such objections to such change as he may desire. If the correction of such error, omission or mistake shall affect the entire assessment, or shall be sufficiently general so that the board shall believe that in furtherance of justice it should give public notice thereof, it shall at least ten days before correcting such error, omission or mistake, publish in the official paper a notice specifying the alleged error, omission or mistake, and that at a time and place to be specified therein it will meet for the purpose of correcting the same, and of hearing any objections which may be made thereto. The board shall meet at the time and place to be so specified, and after hearing all objections which may be made thereto, if, in its judgment, the mistake, error or omission exists, and in furtherance of justice it should be corrected, it shall cause the same to be so corrected.
N.Y. Town Law § 244