Jyotisha (or Jyotishyam from Sanskrit jyotiṣa, from jyótis- "light, heavenly body") is the traditional Hindu system of astrology, also known as Hindu astrology, Nepalese shastra, Indian astrology, and more recently Vedic astrology. The term Hindu astrology has been in use as the English equivalent of Jyotiṣa since the early 19th century, whereas Vedic astrology is a relatively recent term, entering common usage in the 1980s with self-help publications on Āyurveda or Yoga. Vedanga Jyotisha is one of the earliest texts about astronomy within the Vedas. However, some authors have claimed that the horoscopic astrology in the Indian subcontinent came from Hellenistic influences, post-dating the Vedic period.In the epics Ramayana and Mahabharata, only electional astrology, omens, dreams and physiognomy are used.
Jyotiṣa is one of the Vedāṅga, the six auxiliary disciplines used to support Vedic rituals. Early jyotiṣa is concerned with the preparation of a calendar to fix the date of sacrificial rituals.Nothing is written on planets.There are mentions of eclipse causing "demons" in the Atharvaveda and Chāndogya Upaniṣad, the Chāndogya mentioning Rāhu. In fact the term graha, which is now taken to mean planet, originally meant demon. The Ṛigveda also mentions an eclipse causing demon, Svarbhānu, however the specific term of "graha" becomes applied to Svarbhānu in the later Mahābhārata and Rāmāyaṇa.