Savings banks and savings and loan associations may require that a minimum balance in a day of deposit-day of withdrawal account be maintained until the end of any dividend or interest period in which a withdrawal from such account is made; provided, however, that any savings bank or savings and loan association requiring a minimum deposit shall so indicate clearly on all passbooks issued for such accounts.
N.Y. Comp. Codes R. & Regs. Tit. 3 § 67.1