N.Y. Town Law § 24
All elective officers other than town council members, town justices, receivers of taxes and assessors shall hold their respective offices for two years. The terms of office of the town council members first elected after this chapter shall take effect and of the town council members first elected in a town which shall have changed its classification from that of a town of the second class to that of a town of the first class, shall be two years each for two town council members and four years each for two town council members, and thereafter at each biennial town election there shall be elected two town council members for terms of four years each.
The terms of office of the town justices and elective receivers of taxes and assessments shall be four years. The term of office of the assessor shall be six years, unless the town retains a board of assessors, in which case the term for each shall be four years with no more than two assessors to be elected at any biennial election after December thirty-first, nineteen hundred eighty-one except when the unexpired balance of term is being filled in which case three assessors may be elected; when appointed, the term of office shall be as provided by section three hundred ten of the real property tax law. The term of each elective officer shall begin on the first day of January next succeeding the election at which he was elected. The town clerk, the town superintendent of highways, the receiver of taxes and assessments, the town engineer and the town attorney, whenever appointed, shall hold their respective offices until the first day of January next succeeding the first biennial town election held after the time of their appointment. All other appointed officers and employees shall hold their respective offices and positions at the pleasure of the town board, except as otherwise provided by law.
N.Y. Town Law § 24