How it began
Sandford Fleming, a railway engineer in Canada, missed a train in Ireland because a printed timetable gave p.m. where it meant a.m. In 1876 he wrote a memoir called Terrestrial Time, proposing a single 24-hour clock for the whole world and 24 time zones. On February 8, 1879, he presented two papers, Time Reckoning and Longitude and Time Reckoning, to a meeting of the Canadian Institute in Toronto. In them he revised the scheme and tied it to the meridian opposite Greenwich.
How it works
Fleming divided the globe into 24 zones, each one hour wide, which equals 15 degrees of longitude. All clocks within a zone would show the same time. He labeled the zones with letters and proposed that a single prime meridian be chosen as the reference for all of them. After studying shipping numbers he suggested Greenwich. His world clock was to run on a 24-hour day not tied to any local noon.
Who pushed back
At the International Meridian Conference in Washington in 1884, which Fleming helped to convene, the delegates accepted the Greenwich meridian and a universal day of 24 hours beginning at Greenwich midnight. They declined to adopt his zones. The conference stated that the universal day should not interfere with the use of local or standard time where desirable, and treated the zones as a local matter outside its scope.
What changed first
The railways acted before governments did. At noon on November 18, 1883, the railway systems of North America adopted a standardized way of keeping time that used hour-wide time zones. The Canadian Encyclopedia credits Fleming with a crucial part in developing a global system for setting time.
What lasted
Time zones spread country by country after the railways adopted them. By 1929 all the major countries of the world had accepted time zones. The site in Toronto where Fleming first presented standard time is marked by a provincial plaque that calls it the birthplace of standard time, and Fleming is remembered chiefly for this work.
