Cleveland Abbe
In order to compile his information, Abbe required a time-keeping system that was consistent among the stations. To accomplish this he divided the United States into four standard time zones. He published, in 1879, a paper titled "Report on Standard Time". In 1883, he convinced North American railroad companies to adopt his time-zone system. In 1884, Britain, which had already adopted its own standard time system for England, Scotland, and Wales, helped gather international consent for global time. In time, the American government, influenced in part by his 1879 paper, adopted the time-zone system.
Daylight saving time in the United States
By the Energy Policy Act of 2005, daylight saving time (DST) was extended in the United States beginning in 2007. As from that year, DST begins on the second Sunday of March and ends on the first Sunday of November. In years when April 1 falls on Monday through Wednesday, these changes result in a DST period that is five weeks longer; in all other years the DST period is instead four weeks longer. In 2008 daylight saving time ended at 2:00 a.m. DST (0200) (1:00 a.m. ST) on Sunday, November 2, and in 2009 it began at 2:00 a.m. (3:00 a.m. DST) on Sunday, March 8.