Bharatiya Jyotihshastra (History of Indian Astronomy), translated by R. V. Vaidya v2.c14.32

v2.c14.32

It, therefore, shows that works on astrology existed about 800 years before the time of Varāhamihira, which means that our people had developed the knowledge of astrology 4 or 5 centuries before the Śakas. Even though it might not have existed in the same condition in the beginning as at the time of Varāha, it must have gradually developed into that state. The present system of astrology may have come into vogue from the time when Meṣa and other names of rāśis were introduced about 500 years before Śaka era. It was, of course, preceded by the astrological system of the Atharva Veda.