Saṃkhyāvarta (संख्यावर्त्त): Commencement of Yajña at the Dawn of Tretāyuga
अन्तर्हितायां संध्यायां सार्द्धं कृतयुगेन वै / कालाख्यायां प्रवृत्तायां प्राप्ते त्रेतायुगे तदा
antarhitāyāṃ saṃdhyāyāṃ sārddhaṃ kṛtayugena vai / kālākhyāyāṃ pravṛttāyāṃ prāpte tretāyuge tadā
When the twilight of transition that accompanied the Kṛta Yuga had vanished, and the current known as Kāla began to move, then the Tretā Yuga arrived.