... since the map on the Duomètre Unique Travel Time is not used to indicate world time but is rather a setting help for the second zone time. The map thus turns not continually (by connection to the movement) but only by actioning the pushers on the LH side of the case. The numerals circumventing the map indicate the deviation from GMT and are thus in a fixed position in relation to the map. What moves automatically around the map and over these numerals is the sapphire disk to show approximately day and night on the northern hemisphere. This additional display makes the second zone time a 24-hour indication.