Amāvasyā-Pitṛtarpaṇa: Purūravas and the Soma-Based Ancestral Offering (अमावस्या-पितृतर्पण / सोमतर्पण-विधि)
पौर्णमासी व्यतीपाते यदीक्षेतां परस्परम् / यस्मिन्काले समौ स्यातां तौ व्यतीपात एव सः
paurṇamāsī vyatīpāte yadīkṣetāṃ parasparam / yasminkāle samau syātāṃ tau vyatīpāta eva saḥ
In vyatīpāta, if on the full‑moon day the Sun and Moon behold one another, then the moment when the two are equal—this indeed is vyatīpāta.