Vedāṅga Jyotiṣa

The Vedāṅga Jyotiṣa was the first Vedic work completely devoted to astronomy. Many works created before the Vedāṅga Jyotiṣa also discuss aspects of astronomy, but they are not exclusively devoted to it.

It is said to have been created by Ladagha, but the text available now is believed to be edited by some later astronomer because of the classical language used.

It is one of the six Vedāṅga, which are works 'auxiliary' to the ancient Vedas.

It was written in the style of the sūtras.

It was slowly replaced by the Siddhāntas over time. For example, the 27 constellations of the Nakṣatra were slowly replaced by the twelve Zodiac signs, or Rāśis.

It has it's own names for the seasons, months, days of the month, half-days, hours, etc..