PURPOSE: To display easily DST and ordinary time by connecting the display in an area having a daylight saving time and the display in an area where the time is the same as the DST period in said area by an optical display pattern and flickering a plaquette when the area having DST is assigned.

CONSTITUTION: A branch 1c indicates the same segment as the segment of the area name in an area having DST. When an area name "LON" and the branch connecting the same flicker, the ordinary time in "LON", i.e., "12 o'clock 30min" is indicated. The user is simply required to assign the position indicated by the branch flickering together with "LON", that is, "PAR" if he wishes to know the DST in "LON". When "PAR" is assigned, the DST in "LON" and the ordinary time in "PAR" are displayed. The wider area in the display part is made usable as there is no need for any panel cover.