United States Code
Title 15 - Commerce and Trade
Chapter 6 - Weights and Measures and Standard Time
Subchapter IX - Standard Time
Sections 260-267
Current as of April 2002, for current source, see the Legal Information Institute at Cornell or the U.S. House of Representatives.

It is the policy of the United States to promote the adoption and observance of uniform time within the standard time zones prescribed by sections 261 to 264 of this title, as modified by section 265 of this title. To this end the Secretary of Transportation is authorized and directed to foster and promote widespread and uniform adoption and observance of the same standard of time within and throughout each such standard time zone.

1. Duration of period; State exemption
   During the period commencing at 2 o'clock antemeridian on the first Sunday of April of each year and ending at 2 o'clock antemeridian on the last Sunday of October of each year, the standard time of each zone established by sections 261 to 264 of this title, as modified by section 265 of this title, shall be advanced one hour and such time as so advanced shall for the purposes of such sections 261 to 264, as so modified, be the standard time of such zone during such period; however, (1) any State that lies entirely within one time zone may by law exempt itself from the provisions of this subsection providing for the advancement of time, but only if that law provides that the entire State (including all political subdivisions thereof) shall observe the standard time otherwise applicable during that period, and (2) any State with parts thereof in more than one time zone may by law exempt either the entire State as provided in (1) or may exempt the entire area of the State lying within any time zone.
2. State laws superseded
   It is hereby declared that it is the express intent of Congress by this section to supersede any and all laws of the States or political subdivisions thereof insofar as they may now or hereafter provide for advances in time or changeover dates different from those specified in this section.
3. Violations; enforcement
   For any violation of the provisions of this section the Secretary of Transportation or his duly authorized agent may apply to the district court of the United States for the district in which such violation occurs for the enforcement of this section; and such court shall have jurisdiction to enforce obedience thereto by writ of injunction or by other process, mandatory or otherwise, restraining against further violations of this section and enjoining obedience thereto.

Congressional Findings; Expansion of Daylight Saving Time Section 2(a) of Pub. L. 99-359 provided that: "The Congress finds -

1. "that various studies of governmental and nongovernmental agencies indicate that daylight saving time over an expanded period would produce a significant energy savings in electrical power consumption;
2. "that daylight saving time may yield energy savings in other areas besides electrical power consumption;
3. "that daylight saving time over an expanded period could serve as an incentive for further energy conservation by individuals, companies, and the various governmental entities at all levels of government, and that such energy conservation efforts could lead to greatly expanded energy savings; and
4. "that the use of daylight saving time over an expanded period could have other beneficial effects on the public interest, including the reduction of crime, improved traffic safety, more daylight outdoor playtime for the children and youth of our Nation, greater utilization of parks and recreation areas, expanded economic opportunity through extension of daylight hours to peak shopping hours and through extension of domestic office hours to periods of greater overlap with the European Economic Community."

Executive Order Number 11751. Exemptions from Daylight Saving Time and Realignments of Time Zone Limits Ex. Ord. No. 11751, Dec. 15, 1973, 38 F.R. 34725, provided: By virtue of the authority vested in me by section 3(b) of the Emergency Daylight Savings Time Energy Conservation Act of 1973 (Public Law 93-182) (hereinafter ''the Act'') (formerly set out above), section 301 of title 3 of the United States Code, and as President of the United States, it is hereby ordered as follows:

1. The Secretary of Transportation (hereinafter ''the Secretary'') is hereby designated and empowered to exercise the authority vested in me by section 3(b) of the Act (formerly set out above) to grant an exemption from section 3(a) of the Act (which establishes daylight saving time as standard time), or a realignment of a time zone limit, pursuant to a proclamation of a Governor of a State finding that the exemption or realignment is necessary to avoid undue hardship or to conserve fuel in the State or a part thereof.
2. In deciding to grant or deny an exemption or realignment, the Secretary shall consider, among other things, the policy of the United States, as expressed in sections 2 and 4 of the Uniform Time Act of 1966 (80 Stat. 107, 108; 15 U.S.C. 260, 261), to promote the adoption and observance of uniform time within the standard time zones of the United States and the convenience of commerce, as well as possible energy savings, undue hardship to large segments of the population, and the possible impact on the success of and cooperation with the national energy conservation program.
3. In carrying out his responsibilities under this order, the Secretary shall, as he deems necessary, consult with the Department of Health, Education, and Welfare, the Federal Energy Office (or any agency which hereafter may succeed to its functions), and any other interested agency and he may call upon those agencies for information and advice. Each interested department or agency shall assist the Secretary, as necessary, to carry out the provisions of this order.     

Richard Nixon.

For the purpose of establishing the standard time of the United States, the territory of the United States shall be divided into eight zones in the manner provided in this section. Except as provided in section 260a(a) of this title, the standard time of the first zone shall be based on the mean solar time of the sixtieth degree of longitude west from Greenwich; that of the second zone on the seventy-fifth degree; that of the third zone on the ninetieth degree; that of the fourth zone on the one hundred and fifth degree; that of the fifth zone on the one hundred and twentieth degree; that of the sixth zone on the one hundred and thirty-fifth degree; that of the seventh zone on the one hundred and fiftieth degree; and that of the eighth zone on the one hundred and sixty-fifth degree. The limits of each zone shall be defined by an order of the Secretary of Transportation, having regard for the convenience of commerce and the existing junction points and division points of common carriers engaged in interstate or foreign commerce, and any such order may be modified from time to time. As used in sections 261 to 264 of this title, the term ''interstate or foreign commerce'' means commerce between a State, the District of Columbia, the Commonwealth of Puerto Rico, or any possession of the United States and any place outside thereof.

Within the respective zones created under the authority of sections 261 to 264 of this title the standard time of the zone shall insofar as practicable (as determined by the Secretary of Transportation) govern the movement of all common carriers engaged in interstate or foreign commerce. In all statutes, orders, rules, and regulations relating to the time of performance of any act by any officer or department of the United States, whether in the legislative, executive, or judicial branches of the Government, or relating to the time within which any rights shall accrue or determine, or within which any act shall or shall not be performed by any person subject to the jurisdiction of the United States, it shall be understood and intended that the time shall insofar as practicable (as determined by the Secretary of Transportation) be the United States standard time of the zone within which the act is to be performed.

The standard time of the first zone shall be known and designated as Atlantic standard time; that of the second zone shall be known and designated as eastern standard time; that of the third zone shall be known and designated as central standard time; that of the fourth zone shall be known and designated as mountain standard time; that of the fifth zone shall be known and designated as Pacific standard time; that of the sixth zone shall be known and designated as Alaska standard time; that of the seventh zone shall be known and designated as Hawaii-Aleutian standard time; and that of the eighth zone shall be known and designated as Samoa standard time.

Conforming Changes in Time Zone Designations Section 2003(b) of Pub. L. 98-181 provided that:

1. "Any reference to Yukon standard time in any law, regulation, map, document, record, or other paper of the United States shall be held and considered to be a reference to Alaska standard time.
2. "Any reference to Alaska-Hawaii standard time in any law, regulation, map, document, record, or other paper of the United States shall be held and considered to be a reference to Hawaii-Aleutian standard time.
3. "Any reference to Bering standard time in any law, regulation, map, document, record, or other paper of the United States shall be held and considered to be a reference to Samoa standard time."

In the division of territory, and in the definition of the limits of each zone, as provided in sections 261 to 264 of this title, so much of the State of Idaho as lies south of the Salmon River, traversing the State from east to west near forty-five degree thirty minutes latitude, shall be embraced in the third zone: Provided, That common carriers within such portion of the State of Idaho may conduct their operations on Pacific time.

The Panhandle and Plains sections of Texas and Oklahoma are transferred to and placed within the United States standard central-time zone.

The Secretary of Transportation is authorized and directed to issue an order placing the western boundary line of the United States standard central-time zone insofar as the same affect Texas and Oklahoma as follows:

Beginning at a point where such western boundary time zone line crosses the State boundary line between Kansas and Oklahoma; thence westerly along said State boundary line to the northwest corner of the State of Oklahoma; thence in a southerly direction along the west State boundary line of Oklahoma and the west State boundary line of Texas to the southeastern corner of the State of New Mexico; thence in a westerly direction along the State boundary line between the States of Texas and New Mexico to the Rio Grande River; thence down the Rio Grande River as the boundary line between the United States and Mexico: Provided, That the Chicago, Rock Island and Gulf Railway Company and the Chicago, Rock Island and Pacific Railway Company may use Tucumcari, New Mexico, as the point at which they change from central to mountain time and vice versa; the Colorado Southern and Fort Worth and Denver City Railway Companies may use Sixela, New Mexico, as such changing point; the Atchison, Topeka and Santa Fe Railway Company and other branches of the Santa Fe system may use Clovis, New Mexico, as such changing point, and those railways running into or through El Paso may use El Paso as such point: Provided further, That this section shall not, except as herein provided, interfere with the adjustment of time zones as established by the Secretary of Transportation.

Transfer of El Paso and Hudspeth counties, Texas, to mountain standard time zone

Pub. L. 91-228, Apr. 10, 1970, 84 Stat. 119, provided: "That, notwithstanding the first section of the Act of March 4, 1921 (15 U.S.C. 265), the Secretary of Transportation may, upon the written request of the County Commissioners Court of El Paso County, Texas, change the boundary line between the central standard time zone and the mountain standard time zone, so as to place El Paso County in the mountain standard time zone, in the manner prescribed in section 1 of the Act of March 19, 1918, as amended (15 U.S.C. 261), and section 5 of the Act of April 13, 1966 (15 U.S.C. 266). In the same manner, the Secretary of Transportation may also place Hudspeth County, Texas, in the mountain standard time zone, if the Hudspeth County Commissioners Court so requests in writing and if El Paso County is to be placed in that time zone."

Subchapter II of chapter 5, and chapter 7, of title 5 shall apply to all proceedings under this Act, sections 261 to 264 of this title, and section 265 of this title.

As used in this Act, the term ''State'' includes the District of Columbia, the Commonwealth of Puerto Rico, or any possession of the United States.