The concept of the year’s bipartition is fundamental to the structure of the Vedic ritual calendar. This division was marked by two key festive occasions: viṣuvat, aligned with the spring equinox, and mahāvrata, aligned with the winter solstice. During the period in which the Brahmans developed śrauta ritual forms, the observances on these days were integrated into the ritual of gavāmayana (literally, “the cow’s path”), a year-long ritual session known as saṃvatsarasattra. The division of the year into two distinct halves appears intricately connected to its representation within this extended ritual cycle, influencing the performance of individual rituals characterized by their “inversion” in the year’s second half. Examining the concept of “inversion” (āvr̥ tti)—understood here as a technical term in the ritual lexicon—proves particularly insightful, especially considering its varied semantic and ritual implications across the versions documented in Brahmanical literature. These conceptions seem to foreshadow themes that will later receive more elaborate treatment in the Upaniṣadic texts.