The Commission shall have power to perform any and all acts, and to prescribe, issue, make, amend, and rescind such orders, rules, and regulations as it may find necessary or appropriate to carry out the provisions of this chapter. Among other things, such rules and regulations may define accounting, technical, and trade terms used in this chapter; and may prescribe the form or forms of all statements, declarations, applications, and reports to be filed with the Commission, the information which they shall contain, and the time within which they shall be filed. Unless a different date is specified therein, rules and regulations of the Commission shall be effective thirty days after publication in the manner which the Commission shall prescribe. Orders of the Commission shall be effective on the date and in the manner which the Commission shall prescribe. For the purposes of its rules and regulations, the Commission may classify persons and matters within its jurisdiction and prescribe different requirements for different classes of persons or matters. All rules and regulations of the Commission shall be filed with its secretary and shall be kept open in convenient form for public inspection and examination during reasonable business hours.
16 U.S. Code § 825h. Administrative powers of Commission; rules, regulations, and orders
(June 10, 1920, ch. 285, pt. III, § 309, as added Aug. 26, 1935, ch. 687, title II, § 213, 49 Stat. 858.)
“In order to ensure that the provisions of Part I of the Federal Power Act [16 U.S.C. 791a et seq.], as amended by this Act, are fully, fairly, and efficiently implemented, that other governmental agencies identified in such Part I are able to carry out their responsibilities, and that the increased workload of the Federal Energy Regulatory Commission and other agencies is facilitated, the Commission shall, consistent with the provisions of section 309 of the Federal Power Act [16 U.S.C. 825h], review all provisions of that Act [16 U.S.C. 791a et seq.] requiring an action within a 30-day period and, as the Commission deems appropriate, amend its regulations to interpret such period as meaning ‘working days’, rather than ‘calendar days’ unless calendar days is specified in such Act for such action.”