The director is hereby empowered, upon the written application of the directors of a bank, if in his or her judgment the circumstances warrant it, to authorize a bank to postpone, for a period of ninety days and for such further period or periods as he or she may deem expedient, the payment of such proportions or amounts of the demands of its depositors from time to time as he or she may deem necessary. The period or periods of postponement and the proportions or amounts of the demands to be deferred shall be determined by him or her according to the ability of the bank to pay withdrawals. By the regulations prescribed for deferred payments, the director may classify accounts and limit payments to depositors of the several classes differently. The director's orders, regulations and directions shall be in writing and be filed in his or her office, and copies thereof shall be delivered to the bank and be forthwith posted in a conspicuous place in the banking room.