Standard time
In 1870 Charles F. Dowd proposed four time zones based on the meridian through Washington, DC for North American railroads. In 1872 he revised his proposal to base it on the Greenwich meridian. Sandford Fleming, a Scottish-born engineer operating in Canada, proposed worldwide Standard Time at a meeting of the Royal Canadian Institute on February 8, 1879. Cleveland Abbe advocated standard time to better coordinate international weather observations and resultant weather forecasts, which had been coordinated using local solar time. In 1879 he recommended four time zones across the contiguous United States, based upon Greenwich Mean Time. The General Time Convention (renamed the American Railway Association in 1891), an organization of US railroads charged with coordinating schedules and operating standards, became increasingly concerned that if the US government adopted a standard time scheme it would be disadvantageous to its member railroads. William F. Allen, the Convention secretary, argued that North American railroads should adopt a five-zone standard, similar to the one in use today, to avoid government action. On October 11, 1883, the heads of the major railroads met in Chicago at the Grand Pacific Hotel and agreed to adopt Allen's proposed system.
Effects of time zones on North American broadcasting
Local stations and affiliates must schedule their local and syndicated programming around their respective network's feed. Because primetime programs on the East Coast feed are simulcast in two time zones, stations in the Central Time Zone are affected differently from those in the Eastern Time Zone. An hour of syndicated programming time (between 7:00 and 8:00 p.m. in the Eastern and Pacific time zones) is lost in the Central and Mountain time zones since network primetime in those areas starts at 7:00 p.m., forcing stations in Mountain or Central time (or in parts of both zones) to choose between airing their 6:00 p.m. newscast and another syndicated or locally produced program or airing shows in "blocks" preferred by syndicators (for example, "Wheel of Fortune" and "Jeopardy!" together or "Entertainment Tonight" and "The Insider" together).