The United Kingdom was the first country to impose a standard time system. With the growth of rail travel, there was a greater need to organize time measure to ensure the coordination of the movements of different, trains and to guarantee the accuracy of timetables. The first railway to adopt London time as standard was the Great Western Railway in November 1840, and other railways quickly followed suit. In 1847 the Railway Clearing House, an industry-standards body, recommended that London's time be adopted at all stations as soon as possible, and by 1855 most public clocks in Britain were set to London's Greenwich-Mean Time. In the 1880s, however, the legal system caught up with popular practice when the Statutes (Definition of Time) Act received the Royal Assent on 2 August 1880.

Larger nations where there was a significant divergence between the "solar time" in different regions, such...