15 U.S.C. § 263: Designation of zone standard times

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; that of the eighth zone shall be known and designated as Samoa standard time; and that of the ninth zone shall be known as Chamorro standard time. 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. 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. 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.”