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.
Effects of time zones on North American broadcasting
The most common set of programming chosen by stations aligned with the Big Three television networks (ABC, CBS and NBC) is to air a local newscast at 5:00 p.m., national news at 5:30 p.m., another local newscast at 6:00 p.m. and syndicated programming at 6:30 p.m., though some Fox stations that maintain a newscast schedule comparable to stations tied to the Big Three (commonly stations that were former ABC, NBC and CBS affiliates themselves) carry a 60- or 90-minute block of news from 5:00 to 6:00 (or 6:30) p.m. with an additional half-hour of local news in the 5:30 p.m. timeslot as Fox does not air a national evening newscast; a few stations not affiliated with the Big Four networks, such as WGN-TV, KTLA in Los Angeles and WJXT in Jacksonville, Florida, follow a similar scheduling format with their early evening newscasts. Most Big Three affiliates in the Eastern and Pacific time zones follow this early evening newscast model as well, running a 90-minute block of news from 5:00 to 6:30 p.m., particularly if they run a network's national evening newscast at 6:30 p.m. Eastern and Pacific Time. Some stations, regardless of time zone, even show a newscast from 6:00 to 7:00 p.m., which if run on a network station in the Central or Mountain time zones would lead into primetime network programming. Some television stations (such as WKYC and WJW in Cleveland, Ohio, or WJAR in Providence, Rhode Island) have recently begun using the fact that primetime in the Eastern Time Zone begins at 8:00 p.m. to their advantage by carrying a newscast during the 7:00 p.m. hour, generally in order to attract viewers who work longer days and cannot return home to watch a 5:00 or 6:00 p.m. newscast.