In this artwork, how is the Old Czech time scale of the Astronomical dial elucidated?
At the outer edge of the clock, golden Schwabacher numerals are set on a black background. These numbers indicate Old Czech Time (or Italian hours), with 24 indicating the time of sunset, which varies during the year from as early as 16:00 in winter to 20:16 in summer. This ring moves back and forth during the year to coincide with the time of sunset. The outermost diameter of the ring is approximately 300cm (9.8ft).
Schwabacher hour Italian hours Old Czech Time