In 1675, Charles II of England founded the Royal Observatory Greenwich in order to improve global naval navigation (10+7). Many disasters had occurred at sea because sailors did not know the precise longitude (East/West direction) of where they were when out of sight of land. “In 1714, Parliament established a panel of experts, the Board of Longitude, and offered a massive £20,000 reward (equivalent of about £2 million today) to anyone who could solve the problem of finding longitude at sea. It took nearly 60 years for the prize to be claimed. In the end it went not to a famous astronomer, scientist or mathematician, but to a little-known Yorkshire carpenter turned clockmaker, John Harrison. Harrison’s H4 was to change navigation forever. All four of his ground-breaking timekeepers are kept in full working order on display in the Harrison gallery (at the Royal Observatory).”
Royal Observatory Greenwich also helped synchronize clocks around the world. “(Before the 19th century), there were no national or international conventions to set how time should be measured, or when the day would begin and end, or what the length of an hour might be. However, with the vast expansion of the railway and communications networks during the 1850s and 1860s, the worldwide need for an international time standard became imperative.”
In 1884, the Greenwich Meridian was voted the Prime Meridian of the World at the International Median Conference in Washington D.C. “Every place on the Earth is measured in terms of its distance east or west from this line. The line itself divides the eastern and western hemispheres of the Earth – just as the Equator divides the northern and southern hemispheres… the starting point of each new day, year and millennium.” The meridian line is still a favorite place for visitors to pause and stand placing one foot in the beginning of the day and the other foot in the end of the day – thus in two time zones at one time!