A mechanism for displaying the moon phases which has an upper disc or moon dial
(1) and a lower disc or moon indicator (2) that is mounted concentrically
to it. One of these discs is mounted rotatably relative to the other. The moon
dial (1) has two windows (1a, 1b) in order to
account in the display for the different appearance of the moon phases in the northern
and southern hemisphere of the earth.
