No extension of time to answer the statement of appeal or to reply to an answer will be granted by the appeal board unless timely application is made therefor and good cause shown. Such application shall be in writing and shall be served and filed not later than three days prior to the date on which the time to answer or reply will expire. Time to answer or reply may not be extended by stipulation of the parties or their counsel.
N.Y. Comp. Codes R. & Regs. Tit. 8 § 113.13