N.Y. CVP Law § 217

§ 217. Proceeding against body or officer; actions complaining about\nconduct that would constitute a union's breach of its duty of fair\nrepresentation; four months. 1. Unless a shorter time is provided in\nthe law authorizing the proceeding, a proceeding against a body or\nofficer must be commenced within four months after the determination to\nbe reviewed becomes final and binding upon the petitioner or the person\nwhom he represents in law or in fact, or after the respondent's refusal,\nupon the demand of the petitioner or the person whom he represents, to\nperform its duty; or with leave of the court where the petitioner or the\nperson whom he represents, at the time such determination became final\nand binding upon him or at the time of such refusal, was under a\ndisability specified in section 208, within two years after such time.\n 2. (a) Any action or proceeding against an employee organization\nsubject to article fourteen of the civil service law or article twenty\nof the labor law which complains that such employee organization has\nbreached its duty of fair representation regarding someone to whom such\nemployee organization has a duty shall be commenced within four months\nof the date the employee or former employee knew or should have known\nthat the breach has occurred, or within four months of the date the\nemployee or former employee suffers actual harm, whichever is later.\n (b) Any action or proceeding by an employee or former employee against\nan employer subject to article fourteen of the civil service law or\narticle twenty of the labor law, an essential element of which is that\nan employee organization breached its duty of fair representation to the\nperson making the complaint, shall be commenced within four months of\nthe date the employee or former employee knew or should have known that\nthe breach has occurred, or within four months of the date the employee\nor former employee suffers actual harm, whichever is later.\n