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
With four time zones in the contiguous United States, American broadcast television networks generally broadcast at least two separate feeds to their owned-and-operated stations and affiliates, as do cable/satellite channels: the "eastern feed" that is aired simultaneously in the Eastern and Central Time Zones, and the "western feed" that is tape-delayed three hours for those in the Pacific Time Zone. This ensures that a program, for example, that airs at 8:00 p.m. EST on the East Coast is also shown locally at 8:00 p.m. on the West Coast. Networks may also broadcast a third feed specifically for the Mountain Time Zone, on which programs are usually broadcast on a one-hour delay from the Eastern Time Zone. Otherwise, some stations in the Mountain Time Zone use the western feed, while others get a mix of both the Eastern and Pacific feeds.