Conference setting international time begins
This Day in World History – Why does most every country in the world agree on how to determine what time it is? You can thank the International Prime Meridian Conference, which began on October 13, 1884, and lasted nearly ten days. The twenty-five countries that gathered in Washington , D.C., agreed to accept the line of longitude that passed through Britain’s Royal Observatory as the prime meridian—the line of 0° longitude (just as the Equator is 0° latitude). The nations also agreed that the time at Greenwich would be the standard time against which all other times would be compared—Greenwich Mean Time.