Not only was the time once different between countries, even neighboring cities needed to set their clock differently. The need for a unified system emerfed in the late 19th Century, after the industrial revolution. In 1878, the Canadian engineer Sandford Fleming proposed to divide the globe into 24 time zones wherein the time would be the same. It was only in the early 1930s that the Genevan watchmaker Louis Cottier invented a watch displaying the time in all 24 time zones at once. In 1990, Girard-Perregaux presented its first world timer wristwatch and, in 2000, dedicated a whole collection to world timers : the WW.TC.