The board of directors may close the transfer books of any bank or trust company for a period not exceeding fifty days preceding the date of any meeting of stockholders or the date of payment of any dividend or the date for the allotment of rights or the date when any change or conversion or exchange of shares shall go into effect; provided, however, that in lieu of closing the stock transfer books as aforesaid, unless prohibited by the bylaws the board of directors may fix in advance a date, not exceeding fifty days preceding the date of any meeting of stockholders, or the date for the payment of any dividend, or the date for the allotment of rights, or the date when any change or conversion or exchange of shares shall go into effect, as a record date for the determination^* of the stockholders entitled to notice of, and to vote at, any meeting, and any adjournment thereof, or entitled to receive payment of any dividend, or entitled to any allotment of rights, or entitled to exercise the rights in respect of any change, conversion or exchange of shares. In such cases such stockholders and only such stockholders as shall be stockholders of record on the date of closing the transfer books or on the record date so fixed shall be entitled to notice of, and to vote at, the meeting, and any adjournment thereof, or to receive payment of the dividend, or to receive the allotment of rights, or to exercise such rights, as the case may be, notwithstanding any transfer of any shares on the books of the corporation after the date of closing of the transfer books or the record date fixed as aforesaid. If the board of directors does not close the transfer books or set a record date of termination of the stockholders entitled to notice of, and to vote at, a meeting of stockholders, only the stockholders of record at the close of business on the twentieth day preceding the date of the meeting shall be entitled to notice of, and to vote at, the meeting, and any adjournment thereof; except that if prior to the meeting written waivers of notice of the meeting are signed and delivered to the corporation by all of the stockholders of record at the time the meeting is convened, only the stockholders of record at the time the meeting is convened shall be entitled to vote at the meeting, and any adjournment thereof.