Bharatiya Jyotihshastra (History of Indian Astronomy), translated by R. V. Vaidya v2.c12.s2.t5.4

v2.c12.s2.t5.4

The thirteen couplets show that they mention nothing about planets other than the sun and the moon. The method of calculating tithis and nakṣatras is not similar to that of the present day. It mentions the rāśi (sign), aṃśa (degree) and Kalā (minutes) as the units and the subject of ‘shadow’ has been considered at length. Something has been told about the length of the day and the word ‘lagna’ (ascendant) has been used in a somewhat present day sense. The Vasiṣṭha Siddhānta, available at present, is in no way similar to the one existing before Varāhamihira’s time and did not exist in his time. This question will be discussed again later on.