During the development of the Planisphere tool I accidentally came across the picture of Prague astronomical clock. I realized it is actually a sort of the same. A day is displayed here instead of the nigth. Additionally, for reading the time value there are several other dials.
The absence of good looking simulator led me to the conclusion to reuse the same code base and try to mimic the clock with the highest fidelity possible and to allow to set any date or special events like solstices, equinoxes or core Moon phases. Similarly to Planisphere I wanted to offer to set the latitude.
Intended variability could be achieved by the complete vectorization only. This procedure turned out to be the most demanding part of the project. Fortunately, my previous computer graphics experience helped me here a lot. Drop shadows even simulate 3D appearance. The result is 50 kB in size only. It is still enough to preserve the highest quality at any zoom level.