37 C.F.R. § 303.7
(a) Computation. To compute the due date for filing and delivering any document or performing any other act directed by an order of the Copyright Royalty Judges or the rules of the Copyright Royalty Board:
(5) Except as otherwise described in this Chapter or in an order by the Copyright Royalty Judges, the Copyright Royalty Board will consider documents to be timely filed only if:
(b) Extensions. A party seeking an extension must do so by written motion. Prior to filing such a motion, a party must attempt to obtain consent from the other parties to the proceeding. An extension motion must state: