Ahead of the Sun
For most of recorded history, the time of day was a local matter, read from the sun. When the sun stood at its highest point over a town, it was noon there, and a town a few miles to the west reached its own noon a little later. The difference was small but real: Bristol, in the west of England, ran roughly ten minutes behind London, and Penzance further still. Each place kept its own clock by the sky above it, and for communities that rarely needed to coordinate with one another over distance, the idea of a single national time would have seemed not merely unnecessary but faintly absurd.
The railway changed the calculation. A printed timetable promising a departure at nine o'clock was useless if nine o'clock meant one moment in London and another in Exeter; passengers missed trains, and, more dangerously, two trains running on a single track by local clocks set minutes apart could meet where neither driver expected the other. Safe scheduling demanded a single shared reference against which every station along a line could be set. The electric telegraph, spreading alongside the rails, supplied the means: a time signal sent down the wire could put clocks in distant towns into agreement within the same second, something no earlier technology had been able to do.
Britain's railways adopted this logic piecemeal and then quickly. The Great Western Railway ran its trains by London time across its network from around 1840, distributing the hour outward from the capital. In 1847 the Railway Clearing House, the body that coordinated traffic between competing companies, recommended that all railways adopt Greenwich Mean Time, or GMT, and within a year most had done so. The new 'railway time' travelled along the lines into the towns they served, carried by station clocks that the public could see and increasingly chose to trust.
For a period the two times lived side by side, and the friction between them left visible traces. Some town clocks were fitted with a second minute hand, one showing local solar time and the other railway time, so that a traveller could read both at a glance before hurrying to the platform. The tension was practical rather than ideological: shopkeepers, carriers and newspapers found a common clock convenient and adopted it willingly, while a minority clung to the older reckoning. What the double-handed clocks record is not a war over time so much as a transition managed, town by town, in the open.
It is often supposed that standard time was imposed on the country by government decree. The sequence of events suggests the opposite. By the time Parliament acted, the railways had already standardised the working day across the better part of the kingdom. The Statutes (Definition of Time) Act of 1880 made GMT the legal time for Great Britain, but it did so decades after the change had taken hold in practice. The law in this case followed the fact; it ratified a settlement that commerce and the railways had reached on their own, rather than engineering one from above.
The pattern recurred, with local variations, elsewhere. In the United States the problem was larger, for a continent spanned many more degrees of longitude and supported hundreds of separate local times. The solution again came from the railroads rather than the legislature. On 18 November 1883, the American railway companies, acting in concert, divided the country into a handful of standard zones and reset their clocks accordingly, a coordination so abrupt that the day was remembered for its 'two noons'. The federal government did not give these zones the force of law until the Standard Time Act of 1918, thirty-five years later.
The final step was international. In 1884 delegates met at the International Meridian Conference in Washington and agreed to count longitude from a single prime meridian running through Greenwich, providing the fixed reference from which a global system of time zones could be measured. The Canadian engineer Sandford Fleming had argued forcefully for exactly such a worldwide standard. A traveller today, adjusting a watch by a whole hour at a border, treats the uniform clock as part of the natural order. It is worth remembering that it is nothing of the kind: a recent invention, driven by the timetable and the wire, and accepted because it was useful long before it was ever the law.