A polyhedral sundial in the shape of a regular dodecahedron with pentagonal faces. It is the Platonic solid considered the symbol of the universe.

Eleven of its twelve sides were used to make as many sundials, which light up in succession during the day, accompanying the sun from sunrise to sunset.

The five dials inclined downwards were designed for the ancient Italic time system. The five dials inclined upwards were designed to show the true solar time of the place. The horizontal dial was designed with all the hour lines converted to lemniscate, to show the time of the time zone directly.

In this instrument, one can directly compare the time systems used in the past and compare them with our current time zone.