Know when and where with a Geochron

The Geochron is a global time indicator with a moving map driven by a clockwork mechanism and backlit with internal shutters. There are scales on the bottom to show the day of the week anywhere in the world and scales across the top to indicate the time of day anywhere. A separate scale gives the month and date. It also shows the sun’s position in the sky from anywhere on the planet. An analemma moves between the two tropics, indicating the sun’s position over the course of a year.

Manufactured in Redwood City, California, the Geochron was invented circa 1963 by James Kilburg, an electrical engineer originally from the Grand Duchy of Luxembourg. His son, James Jr., and Robert Williamson presently run the company, Geochron Enterprises, Inc. (899 Arguello St., Redwood City, CA 94063-1308; phone 800/342-1661 or 650/361-1771, e-mail or visit

I bought my Geochron in 1991 and it has run perfectly ever since. In November ’05 I drove down to the Bay Area and dropped my Geochron off at the factory to give it a general tuneup and have an up-to-date map installed. Bob Williamson gave me a tour of their facility and told me they ship a couple of thousand Geochrons a year, each ready-wired for the country it is going to. At that time, the standard model cost $1,595.

Vancouver, WA