Part 1 - Development in the Saṃhitā Period (Introduction)

The form of Karman and the conception and accordingly the utility of Jyotiḥśāstra carries a variance in the culture. The correlation thereby appears phase wise and can be divided into five broad periods, the Saṃhitā Period, the Brāhmaṇa Period, the Upaniṣad Period, the Smṛti or Vedāṅga Period and the post-Greek or Varāha Period.

In the early Saṃhitā period the foremost aspect of Vedic religion appears in a mythological form. The Ṛgveda is an expression of human conception about the natural powers in the forms of personifications and worship of an aggregate of nature and light deities, invoked in the sacrificial rituals.

The attributes of these deities were essentially the multiple forms of the animated cosmos personalized by the Vedic men in communion with human qualities and actions. Worship of these deities were supposed to sub serve their ideals and purposes regarding the present life and the future one.

While the speculations related to cosmology were getting pantheistic (Ṛgveda-saṃhitā X.90), the elementary study of Sun and Moon as technical time measuring devices was getting systematized into various divisions of cosmos brought forth by the luminaries, its qualities being studied for ritual utility from Vedic point of view. Ritual actions were already in an organized form with worship in Atharvaveda in the form of domestic and magical rites, more so in the Yajurveda where correct performance of sacrifices was the principal aim, the nature deities of Ṛgveda being loosely connected with the actual ritual. Proper time to conduct the sacrificial rites was the chief requisite for which the actions of heavenly bodies were observed. Since the sacrifices came with specific purposes relative to man as well as cosmos, unraveling the skies for its fulfillment seemed to be a regular practice.

The Correlation exists in the above senses in the Saṃhitās.