28 U.S.C. § 2072. - Rules of procedure and evidence; power to prescribe

(a) The Supreme Court shall have the power to prescribe general rules of practice and procedure and rules of evidence for cases in the United States district courts (including proceedings before magistrate judges thereof) and courts of appeals.

(b) Such rules shall not abridge, enlarge or modify any substantive right. . . .

§ 2074. Rules of procedure and evidence; submission to Congress; effective date

(a) The Supreme Court shall transmit to the Congress not later than May 1 of the year in which a rule prescribed under section 2072 is to become effective a copy of the proposed rule. Such rule shall take effect no earlier than December 1 of the year in which such rule is so transmitted unless otherwise provided by law. ...