N.Y. Comp. Codes R. & Regs. tit. 4 § 5.3 : DEPARTMENT OF CIVIL SERVICE — Regulations Of The Superintendent Of Financial Services — Personnel Changes — Resignation

(a) Resignation in writing. Except as otherwise provided herein, every resignation shall be in writing.
(b) Effective date. If no effective date is specified in a resignation, it shall take effect upon delivery to or filing in the office of the appointing authority. If an effective date is specified in a resignation, it shall take effect on such specified date. However, if a resignation is submitted while the employee is on leave of absence without pay, such resignation, for the purpose of determining eligibility for reinstatement, shall be deemed to be effective as of the date of the commencement of such absence. Notwithstanding the provisions of this subdivision, when charges of incompetency or misconduct have been or are about to be filed against an employee, the appointing authority may elect to disregard a resignation filed by such employee and to prosecute such charges and, in the event that such employee is found guilty of such charges and dismissed from the service, his termination shall be recorded as a dismissal rather than as a resignation.
(c) Withdrawal or amendment. A resignation may not be withdrawn, cancelled or amended after it is delivered to the appointing authority, without the consent of the appointing authority.

N.Y. Comp. Codes R. & Regs. Tit. 4 § 5.3