Chronos is an Acupuncture software indicating the AcuPoints opened for a given Date and Hour.
These points must match the rules of the "Zi Wu Liu Zhu" and "Ling Gui Ba Fa"
methods of the Traditional Chinese Medicine,
which use the concepts of Heavenly Stem and of Earthly Branch of the Chinese Calendar.
It deals with the Gan Zhi system of the 60 combinations [Heavenly Stem (Tian Gan) Earthly Branch (Di Zhi)], for the Day and for the Hour.
This naturally refers to the Solar Chinese Calendar.