[20021217]98-99C_夏时制时间.pdf

Congressional Research Service The Library of CongressCRS Report for CongressReceived through the CRS WebCurrently, Daylight Saving Time (DST) isobserved in the United States from 2:00 a.m. onthe first Sunday in April until 2:00 a.m. on thelast Sunday in October. The following statesand territories do not observe DST: Arizona,Hawaii, part of Indiana, American Samoa,Puerto Rico, and the Virgin Islands.Order Code 98-99 CUpdated December 17, 2002Daylight Saving TimeHeidi G. YackerInformation Research SpecialistInformation Research DivisionSummaryCurrently, in most parts of the United States, timepieces are moved forward onehour in the spring and back one hour in the fall to provide an extended daylight periodduring the summer months. This is known as Daylight Saving Time (DST). Muchdebate and many changes led to this present practice. Questions regarding DST andsuggestions for changes persist. This report provides a brief history of the issuessurrounding DST, an outline of the legislation that created and modified it, and a list ofreferences to more discussions. Whenever the law or regulations governing DST changein the United States, this report will be updated.Development of Dayligh