Man’s Natural Timepiece
From the first crude sundials that divided the days into vague and irregular intervals, to the finest navigational chronometers that maintain split-second accuracy over long periods, our basic source of time has always been the rotation of the earth we live on and the apparent motion of the sun that this rotation causes. Even before any concept of time existed, the daily alternation of light and darkness must have regulated man’s activities, as it does the activities of animals today. As recently as one hundred thirty years ago, every city, town and hamlet on earth observed its own local time based on the instant that the sun reached its zenith at that locality, and "high noon" was the universal time for setting clocks and watches.

The Time Zone Problem
Those simple and straightforward days of Local Sun Time ended when the first transcontinental railroads ushered in the era of modern long-distance transportation. The time confusion for travelers and trainmen became so great on long trips that in the 1870s the 24 "standard" world time zones we know today were set up by international agreement. These zones solved one problem but created another. Today, in our age of high speed jet travel, electronic communications, and growing international involvement, more and more people need to know, or are interested in knowing, what time it is somewhere else — often halfway around the earth. The problem that time zones created is that the ordinary clock and watch are highly inadequate for telling time on a global basis.

The Inadequacy Of The Clock
Conventional clocks are essentially local time indicators and no more. (The last basic The Inadequacy Of The Clock innovation in the design of clocks — outside of improved accuracy and minor gimmickry — was back in the 17th century when someone added the minute hand to the theretofore single-handed clock dial.) Because clocks and watches present time as an abstract (and sometimes meaningless) number, learning the time in another part of the world is a matter of working with other abstract numbers (time zone conversion factors) as well as figuring out whether it is A.M. or P.M., what day of the week and what date it is. Since there are at least 34 local world time zones (24 standard and 10 nonstandard) the problem is not simple. And, for this same reason, the idea of multiple dials or clocks for keeping track of world time is impractical.

Geochron: The New World Timepiece
Geochron solves all these problems in one stroke by combining the answers to the two questions "What time?" and "Where?" in a single easy-to-read graphic analog. Physically, Geochron looks like a framed world map, about 3 by 2 feet in size. It is designed to be hung on the wall. The colorful map itself, a precision Mercator projection printed on dimensionally stable Mylar, 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.

Reading World Time On Geochron
The time zone arrows point to a stationary time scale across the top of the map that reads from midnight to the left, through noon in the middle, to midnight again at the right. To read the time in any standard zone in the world, you simply find that place on the map and follow the zone boundaries to the arrow which points out the correct time. Certain nonstandard and pocketed zones have boundaries that do not extend to an arrow. These are marked with a letter and a number. The letter tells you which arrow to read and the number shows the deviation from standard time. In the case of India, for example, the designation is E + 30. This means that you add 30 minutes to time you read on the E pointer. Simple addition of a fraction of an hour in the case of the 10 nonstandard zones is the only calculation ever required in reading the Geochron.

Reading The Date And Day Of The Week On Geochron
Since the map is moving slowly across the frame from left to right, the International Dateline crosses the frame once each day. The days of the week observed on either side of the Dateline are displayed in windows near the bottom of the map. The date and month for these two days are likewise shown on an indicator mounted at the bottom of the Geochron.

Geochron: Graphic Analog Of Day And Night
Perhaps the most fascinating thing about Geochron is that it shows the exact portions of the earth that are in daylight, and those that are in darkness, at the very instant you are observing Geochron. The brightly illuminated pattern in the center of the map delineates those areas that are in daylight. The left edge of this pattern is the line of sunrise as it sweeps across the earth, and the right edge is the line of sunset. Because the length of the day is changing daily as the earth progresses through its seasons, the light pattern on Geochron changes also, almost imperceptibly, from day to day. Thus, with Geochron you can read the time of sunrise and sunset and the relative length of day and night for any latitude.

This illuminated pattern also shows the progress of the seasons during the year, from winter through spring, summer, fall and back to winter again. Such heretofore abstract phenomena as the summer and winter solstices on the dates of the longest and shortest days of the year, and the vernal and autumnal equinoxes, when the day and night of equal length, are clearly and graphically shown by the Geochron light pattern.

Because Geochron is a graphic analog, the viewer soon gains an instinctive appreciation of what time it is everywhere. It no longer becomes necessary to read an abstract number to know if it is an appropriate time to call someone in Paris, France, or Sydney, Australia. A glance at the light pattern on the map instantly tells you whether it is daylight at those places or the middle of the night.

Other Uses For Geochron
Geochron is provided with two simple basic controls that allow it to be used for far more than just telling time. One knob at the base of the unit allows you to move the map horizontally across the frame. It is used basically to set the correct time on the Geochron scale when it is first plugged in. But, by moving the map, you can also determine the time of sunrise and sunset at any locality on that day and see the relative effect of latitude on these times.

The second knob at the base of the unit allows you to set the date indicator to any day of any month in the year. Since the light pattern mechanism is coupled to the date indicator, this also changes and shows the light condition on earth at that time of year. This feature has been found valuable by educators, motion picture producers, military men, as well as by the average person who just wants some help in planning his vacation.

Geochron also shows the exact zenith position of the sun at any time on any date and graphically indicates the relationship between Apparent Solar Time and Mean Solar Time as expressed in the Equation of time. This is indicated by a small black dot that follows the zenith position of the sun as it traverses the earth.

Geochron: Modern Successor To The Wall Clock
Geochron is the new world timepiece for those in business, government or private affairs whose timetelling needs or interests extend beyond the boundaries of their own local time zones. It can truly be called the modern successor to the wall clock in this modern age of high-speed international travel, communication and world involvement.

WHY CONVENTIONAL CLOCKS ARE OUT OF TIME.

As technology continues to advance and the concept of a "global economy" gains more and more acceptance, it becomes increasingly necessary to know, or at least to be aware of, the time in other parts of the world.

For more globally-minded people it is even more critical to know the hours of daylight throughout the world.

Yet even the most advanced clocks of today are merely time indicators, devoid of any other vital information. That is, except for the Geochron.

THE DIFFERENCE IS NIGHT AND DAY.

In addition to providing you the time anywhere in the world (not to mention a refresher course in geography), the Geochron also communicates important, constantly-changing information not available from any other source.

As a result of its simultaneous, horizontal, and vertical movement, the sun button describes a figure eight pattern, crossing the "mean noon" four times. The pattern is called the "Ana lemma."

As you can see from the photos on this page, this sunlight distribution pattern changes perpetually, as days and seasons progress.

24 HOURS. 40 TIME ZONES.

You probable already know how the earth is divided into 24 "standard" time zones. But did you know about the 16 additional "non-standard" time zones?

Don't worry. The Geochron has them all covered, all year long -- even during periods of daylight-savings time.

What's more, the map on every single Geochron we make is designed to reflect changes in the world order (for example, the unification of Germany, the breakup of the former Soviet Union).

The Original Kilburg Geochron features a minute analog, in the upper right hand corner, to make it even more precise.

HOW TO TELL TIME WITH GEOCHRON.

What about those non-standard zones we just mentioned? Simple. Those non-standard and pocketed zones have boundaries that do not extend to an arrow. Instead, they're marked with a letter and a number.

The letter, derived from international radio call letters, tells you which arrow of the Geochron to read, while the number shows the number of minutes the region deviates from standard time. For example, the designation of India is E + 30, which means you add 30 minutes to the time you read on the E pointer.

You've just completed the most difficult calculation of international time a Geochron owner ever has to compute. Congratulations.

WHAT DAY IS IT, ANYWAY?

Reading the date and day of the week is a snap with Geochron. Since the map is moving from left to right, the International Dateline crosses the frame once each day. The days, date and month observed on either side of the Dateline are each displayed via indicators mounted at the Geochron's bottom.

What Makes a Geochron Tick?
Whether it's the Original Kilburg, the standard, an executive model or one of our boardroom models, every single Geochron we make is hand-crafted in the United States.
Each gear is individually hand-cut to ensure optimum synchronization. Each world map is custom printed on state-of-the-art Mylar film using specially formulated inks designed to make the map resistant to ultraviolet light. And by the time each Geochron is hand-crafted for shipment anywhere, it has been personally inspected, passing through 24 designated key inspection points.

If you require a little more technical information, here are some other things to know about the Geochron.

Mounting - The Geochron can be mounted on any flat surface in the same manner as a picture. Standard surface mounting brackets are supplied. If you prefer, it can also be recessed into the wall with special flush mount brackets that must be ordered separately. The recess opening required is 33 5/8" x 21 3/8" x 4". Installation instructions are supplied with each unit.

Manual controls - The Geochron has three simple control knobs. Two are located at the base of the unit and are used primarily for the initial setting. One moves the map horizontally to set the time and day of the week. It's also used to determine time of sunrise, sunset and the number of daylight hours at any location at a time other than current. The other knob sets the date indicator and light pattern. A third knob controls the minute dial located at the Geochron's upper right hand corner.

Available housing - The Geochron comes in seven laminate finishes. Princess Plonge' leather is also available, as well as custom wood housings with various accent moldings. Other custom finishes are available at additional cost. Geochron's metal trim pieces are available in a variety of anodized finishes. Specify choice when ordering. Finish samples are available upon request.

Electrical - Geochron is supplied with a choice of standard currents, including 120 and 220 volt, 50 and 60 cycle, etc.

Illumination - Uses two easily replaceable F15T8D fluorescent tubes. An electric switch at the base turns the lights on or off without disturbing the timing mechanism.

Protective glass - A brilliant glass pane shields the facing side of the Mylar world map.

Map credits - The Geochron map is reproduced in part from Chronoflexpositives of the U.S. Naval Oceanographic Chart #1262. Legal time zone information is based on data from the U.S. Department of Defense Mapping, Time Zone Chart #76. Delineation of the time zones and designs of the time scale are original with Geochron.