Wikipedia
Jyotisha
Jyotisha (, IAST: Jyotiṣa) is the science of tracking and predicting the movements of astronomical bodies in order to keep time. It refers to one of the six ancient Vedangas, or ancillary science connected with the Vedas – the scriptures of Hinduism. This field of study was concerned with fixing the days and hours of Vedic rituals.
The term Jyotisha also refers to Hindu astrology, a field that likely developed in the centuries after the arrival of Greek astrology with Alexander the Great, their zodiac signs being nearly identical.