The corpus, every claim citable.

Pañcasiddhāntikā III.21 (505 CE) states that the summer solstice once turned from the middle of Āśleṣā — "then the ayana was right" — but at present begins from Punarvasu: a shift of about 23°, roughly 1,700 years of equinoctial precession separating the old record from current observation. Hipparchus discovered precession c. 130 BCE; this verse documents the Indian tradition registering the same drift by checking its inherited solstice positions against the sky.

The Panchasiddhantika: The Astronomical Work of Varaha Mihira · tr. G. Thibaut & Sudhakara Dvivedi, 1889