The sundial, created by the monastery painter Joseph Anton Morath, was built around 1780 on the eastern office building near the Kurgarten.
It not only shows the time, but also the month. Chronos, the god of time, can be recognised on it, holding the time band in his right hand and the pointer in his left. A special feature is the vertical figure-eight loop, which makes the sundial a so-called 'midday clock'. There is a perforated disc at the end of the "Chronos" hand rod. When the point of light passes through this perforated disc onto the figure-of-eight loop and crosses the corresponding date point, it is 12 noon (local time) in St. Blasien. This device was once used to regulate the mechanical church clock in the cathedral bell tower.