Why Standard Time Was Invented

[A] Until the middle of the nineteenth century, a town set its clocks by the sun. Noon was the moment the sun stood highest over that particular town, which meant that noon in one place was several minutes away from noon in the next. [B] For people who travelled at walking pace, this caused no difficulty whatsoever.

[C] Railways made it intolerable. A timetable has to state a single departure time, and a line running east to west crosses dozens of local noons. British companies solved the problem by ignoring local time altogether and running everything on the clock at Greenwich, a practice so closely associated with the industry that it was known as railway time. [D] Towns resisted, sometimes for years, and a few public clocks were fitted with two minute hands so that both times could be read at once. The wider system of world time zones, agreed internationally in 1884, simply extended the railways' solution across the globe. It is worth noticing what this means: the hour shown on a clock today is not an astronomical fact about a place but an administrative convenience, chosen to make timetables possible.