The horizon line is a direct result of the sundial's location, that is to say of the data you enter in the Place tab of the input box.
o If the location is correct, the horizon line will be horizontal on the final sundial
o If the location is wrong, the horizon line will be tilted. However the hour lines and the diurnal arcs will be perfectly correct, but their ends will be either truncated or extended
Note: If the axes of the sundial are drawn tilted, a horizontal line on the final sundial will be represented tilted on the diagram given by Calcad. In the same way, a line represented horizontally on the diagram will be tilted on the final sundial.