(1) A witness summons is issued on the date entered on the summons by the court office.
(2) A party must obtain permission from the court when that party wishes to have —
(a) a witness summons issued less than 21 days before the date of the hearing; or
(b) a summons issued for a witness to attend court to give evidence or to produce documents on any date except the date fixed for the trial or the hearing of any application.
(3) An application for permission under paragraph (2) may be without notice but must be supported by evidence on affidavit.
(4) The court may set aside or vary a witness summons.