Surya Siddhanta
दिनाब्दमासहोराणाम् अधिपा न समाः कुतः। कथम् पर्येति भगणः सग्रहो +अयम् किम् आश्रयः॥
Whence is it that the regents of the days, years, months, and hours (hora) are not the same? How does the circle of asterisms (bhagana) revolve? what is the support of it with the planets?
english translation