Adhyaya 4: अहोरात्र-युग-मन्वन्तर-कल्पमान तथा प्रलयान्ते सृष्ट्युपक्रमः
तावच्छती च वै संध्या संध्यांशश् च कृतस्य तु त्रिशती द्विशती संध्या तथा चैकशती क्रमात्
tāvacchatī ca vai saṃdhyā saṃdhyāṃśaś ca kṛtasya tu triśatī dviśatī saṃdhyā tathā caikaśatī kramāt
For the Kṛta Yuga, the twilight junction (sandhyā) and its concluding portion (sandhyāṃśa) are each of the same measure—four hundred years. Thereafter, in due order, the sandhyā measures are three hundred, two hundred, and one hundred years for the succeeding yugas.
Suta Goswami
It frames Linga-worship within Shiva’s governance of time (kāla): as yugas change and dharma declines, sādhana and ritual intensity are understood relative to the yuga’s sandhyā measures.
By defining cosmic time-junctions, it implies Shiva as Pati—Lord of kāla and niyati—who orders creation’s rhythms, within which the pashu seeks liberation from pāśa.
It highlights kāla-viveka (discernment of time): aligning vrata, japa, and pūjā with yuga-conditions—an underlying principle for Pāśupata discipline and Purāṇic observance.