MC4181-388 series world time zone master clocks are available in rack mounted and wall mounted versions. Both have the same powerful operating program. They are used as a master control for ATS world time zone clocks to provide a complete stand-alone system for up to 15 world time zones. GMT (Greenwich Mean Time) is used as the reference time. GMT time, GMT date, GMT day of the week, time zone offsets (including 1/2 hour offsets), and any seasonal adjustments are easily programmed for up to 15 different world time zones, using the built-in keyboard and alpha-numeric display. Auto-prompt, cursor guided programming makes set up quick and easy. Time and zone information are transmitted once each minute over simple 2-conductor cable to the remote ATS world time zone clocks. Up to 15 zones are provided. Multiple clock displays can be connected to display the same 15 zones in other locations up to 2000ft away. In addition to the ATS world time zone clocks, the ATS AE series large digital clocks with the RS232 input option can also be connected to this system. CC2000 series digital clocks can be used to display zone 15 data only.