Patent ID: 8221125

Claim:
An electronically controlled graphic display system for determining a local civil time of two or more time zones in the world comprising: (a) a cartographic projection of the earth surface or a portion thereof, having an outer periphery, the projection being divided into a plurality of geographical time areas each corresponding to a civil time zone, the geographical time areas being coded so as to be visually distinguishable at least from adjacent areas; (b) a series of time zone time markers which are similarly coded to correspond with associated, geographical time areas, such markers being disposed along at least a portion of the outer periphery of the cartographic projection; (c) a time scale including a plurality of time indicators disposed along said portion of the outer periphery of the cartographic projection, the time zone time markers being positioned to correspond to respective, associated time indicators included in the time scale whereby each time indicator is respectively associated with a geographical time area provided on the projection; (d) an electronic graphic display for presenting the cartographic projection of the earth surface or a portion thereof along with the timescale and time zone time markers, and (e) an electronic display controller connected to the graphic display having access to a clock capable of providing the local effective civil time corresponding to each geographic time area, and having access to a digital record database containing a list of the geographic time areas, their locations on the cartographic projection, and the effective date that each geographical time area adjusts its local civil time to introduce or remove daylight savings time; wherein the controller, by reference to the digital database, adjusts the display to maintain the correspondence between the time zone time markers and the associated time indicators to display the actual time in each geographical time area by: i) periodically changing the relative positions of the time zone time markers disposed along the outer peripheral portion of the cartographic projection with respect to the time indicators such that the alignment of the time zone time markers with respect to the time indicators continues to indicate the local time of geographical time areas, or ii) periodically changing the coding of the geographical time areas without changing the coding of the associated time zone time markers such that the geographical time areas have the same coding as time zone time markers that are aligned with the appropriate time indicators to indicate the correct, actual, time within each of the geographic time areas for a given calendar date, so as to accommodate for changes with respect to daylight savings time.