2006 New York Code - Lien Date.

 
    §  902.  Lien date. The amount of all taxes, special ad valorem levies
  and special assessments levied upon any parcel of real property  by  the
  board  of  supervisors  shall, except as otherwise expressly provided by
  law, be and become a lien thereon as of the first day of January of  the
  fiscal year for which levied and shall remain a lien until paid.