When twenty-five dollars or more is demanded, the complaint shall be served on the defendant not less than twenty days and when less than that sum is demanded not less than five days before the day therein fixed for trial. But if the plaintiff shall make out that he is apprehensive of losing his debt by such delay and the magistrate considers that there is good reason therefor (the grounds of such apprehension being set out in an affidavit and served with a copy of the complaint) he may make such process returnable in such time as the justice of the case may require.