Vikala, kala, bhaga, bhagana

To understand Vikala, kala, bhaga and bhagana, we refer to the following shloka from Surya Siddhanta

The above shloka means Sixty vikala is one kala, sixty units (kala) is one bhaga, it is said this way that, thirty units (bhaga) makes one rashi, twelve rashi makes one bhagana. The Vikala, Kala, Bhaga,Bhagna are the Units of Angle used in Surya Sidhnata. This knowledge about the division of the angles in a circle is one of the earliest knowledge. Today, Vikala, Kala and Bhaga are coterminous with the Second, Minute and Degree respectively. Please note that Rashi was also used as a unit of angle.