Measuring time may seem simple, but the idea of an exact hour is a relatively recent construction. For centuries, each city lived by its own rhythm, until new demands—such as the railway—required synchronization. From there, increasingly precise clocks, time zones, and technologies like GPS began to weave an invisible network that coordinates the world in real time. What we now take for granted is, in fact, the result of a chain of decisions and innovations that transformed everything from daily life to the functioning of the global economy.