N.Y. County Law § 151 – Organization of board

1. The members of the board of supervisors shall organize the board and select a chairman on or before the eighth day of January in each year. The board shall annually, by resolution duly adopted during the month of December, fix the date, time and place of the meeting to organize the board. The board may provide by local law that the members of the board shall meet to organize and select a chairman on or before the eighth day of January in each even-numbered year. The clerk of the board of supervisors shall serve upon each member a notice stating the date, time and place of each meeting to organize the board and that a chairman will then be selected. The notice shall be in writing and shall be served by mail addressed to each member at his last known post-office address at least forty-eight hours before the date of the meeting.
2. In the event of the death, inability or failure of the clerk of the board of supervisors to call any such meeting or to serve such notices, the county clerk of the county shall call the meeting to organize the board and select a chairman on or before the fifteenth day of January following. Notice of such meeting shall be served by the county clerk in like manner and time as provided for service of notice by the clerk of the board in subdivision one.
3. At such organization meeting, or at an adjourned meeting not later than February first, the board shall select a chairman and may select a vice-chairman.
4. The term of office of the chairman shall expire at the end of the calendar year in which he is selected, unless the board shall provide by local law for the selection of the chairman in January of each even numbered year, in which event the term of office of the chairman shall be for a term expiring with that of his term of office as supervisor.
5. In the event of a failure of the board of supervisors to select a chairman on or before February first, the county clerk of the county shall appoint a member of the board as chairman, who shall serve until the end of the calendar year in which he is appointed.
6. In the absence of the chairman and the vice chairman, if one has been selected, at any meeting of the board of supervisors, the members present and voting, by majority vote, shall select a member of the board to serve as acting chairman at such meeting. The acting chairman shall have and exercise all the powers and duties of the chairman at the meeting over which he is called to preside.
6-a. In the absence of the chairman, the vice-chairman, if one has been selected: a. shall preside over each duly constituted meeting of the board; b. shall have and exercise all the powers and duties of the chairman at any meeting over which he is called to preside; c. shall have and exercise those additional powers and duties authorized by resolution of the board, provided such resolution shall specify:
1. (i) the dates during which the vice-chairman may exercise those powers and duties; and
2. (ii) that the powers and duties authorized to the vice-chairman shall not be exercised by the chairman during that designated time period.
7. In case of a vacancy in the office of chairman, the clerk of the board of supervisors shall call a meeting of the members of the board upon like notice as provided in subdivision one, at which a successor shall be selected chairman who shall be a member of the board. The person so selected shall serve as chairman of the board for the unexpired term of the previous chairman. In the event of the failure of the board to select such chairman within thirty days after the vacancy shall have occurred, the county clerk shall appoint a member of the board as chairman, who shall serve until the end of the calendar year in which he is appointed.