N.Y. Jud. Law § 416

§ 416. Copy of impeachment served on defendant. The president of the\nsenate must thereupon cause a copy of the articles of impeachment, with\na notice to appear and answer the same, at the time and place appointed\nfor the meeting of the court, to be served on the defendant, not less\nthan twenty days before the day fixed for the meeting of the court.\n