If the president and vice president of the charitable corporation resigned last week and you want to know how long do you have to wait to call a special meeting to vote on new officers, I suggest that you carefully read the approved bylaws of this corporation for your answer.The presumed approved bylaws set forth the way this corporation operates with respect to officers, members and its board of directors. If you cannot locate the bylaws for this corporation, then your answer would be determined by your state's statute on the subject. If you cannot locate the bylaws, I suggest that you consult with an attorney who practices corporation law to assist you.