What is "geochron"

Geochron, Inc. is an American company founded by James Kilburg, an inventor from Luxembourg. It is also the name of their flagship product, the Geochron Global Time Indicator. The Geochron was the first world clock to display day and night on a world map, showing the familiar "bell curve" of light and darkness.

The Geochron employs an intricate analog clockwork mechanism for its display, that shows the month, date, day of the week, hours and minutes, the areas of the world currently experiencing day and night, and the meridian passage of the sun. The main display is dominated by a world map, with time zones prominently indicated. At the top of the map are arrows corresponding to each time zone. As each day progresses, the map is scrolled from left to right by gear mechanisms, and the arrows for each time zone shift their positions relative to a stationary band fixed at the top that has a horizontal series of numbers representing hours. The viewer may read the time by seeing what number his time zone's arrow is currently pointing to. The map is backlit, and a mechanism behind the map defines well-lit and shaded areas that are also stationary relative to the movement of the map. In this way, as time progresses, different areas are shown to be experiencing daytime and night. The center of the lit area lines up with the 12 noon on the stationary time strip. There is also a day-and-month readout below the map, and a minutes readout above.

Each Geochron is assembled upon demand, with prices starting at above $1500. Ronald Reagan presented a Geochron to Mikhail Gorbachev in the 1980s as an "example of American ingenuity." The Hubble Space Telescope control center at Goddard Space Flight Center uses a Geochron in its day-to-day operations. The Smithsonian Institution has called the Geochron the "last significant contribution in timekeeping."

After many years in the San Francisco Bay Area, Geochron Enterprises was sold and moved to Portland, OR to become Geochron, Inc. The product is still produced by hand and manufactured at the factory in Portland.