Please explain the method of calculating Subh Saadiq.

Answer

We do not know of the method of calculating Subh Saadiq. We do not know if a valid method of calculating Subh Saadiq exists or not. The way of determining Subh Saadiq is to observe the physical phenomenon in the sky. This is described in Kitaabus Salaat, in Beheshti Zewer and other elementary books of Salaat, which are available in English in abundance.