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.
Chamorro Time Zone
Chamorro Standard Time shares the same time as Australian Eastern Standard Time.The Mariana Islands were not part of any time zone legislated by the U.S. Congress until the Chamorro time zone was established by Public Law 106-564 on December 23, 2000. Prior to 2000, Guam's standard time was based on territorial Public Law 5-25 (1959) which designated the time Guam Standard Time. The law (Guam Code Annotated, Title 1, Section 1010) was established long before the Northern Mariana Islands came under U.S. sovereignty in 1986, and still remains in the book today despite federal overlap.