The Original Geochron
The Geochron allows any observer to determine what time it is anywhere in the world. Physically the Geochron looks like a framed world map, about 2×3 ft. in size. The colorful map itself is an endless belt that is driven slowly from left to right by an electric clock motor in synchronism with the rotation of the earth. All known legal time zone boundaries are delineated on the map by dark blue lines which in most cases, converge on lettered pointers on the top edge of the map. These letters identify the standard time zones and also represent the short wave radio prefix for that zone. 
Specifically, the Geochron illustrates:
- Legal time zones
- Greenwich Mean time
- Greenwich Apparent time
- Local Apparent time
- Moment of sunrise
- Moment of sunset
- Duration of daylight
- Sun’s meridian passage
- Sun’s equation of time
- Degrees of latitude and longitude
Two Models of Geochron
There are two models of the Geochron World Clock: Original Kilburg and The Boardroom. Each model has slightly different features, though functionality is exactly the same. The map runs the same, the seasons change the same and both include a minute analog dial in the top right hand corner of the front panel. This dial allows for more accurate time keeping because it displays the exact minute after the hour and runs in unison with the map.
The major differences are aesthetic. Upgrade panels are available on the Original Kilburg model. These upgrades are aside from the seven vinyls available at an entry level price. The upgrades include; Stainless Steel, Powder Coats, Anodized Aluminum and Natural Wood veneers. Boardroom models feature a special “cove molding” on their natural wood front panels.