सूर्यरथनिर्णयः (चन्द्रस्य पक्षवृद्धिक्षयविधानम्)
पिबन्ति द्विकलं कालं शिष्टा तस्य कला तु या निसृतं तदमावास्यां गभस्तिभ्यः स्वधामृतम्
pibanti dvikalaṃ kālaṃ śiṣṭā tasya kalā tu yā nisṛtaṃ tadamāvāsyāṃ gabhastibhyaḥ svadhāmṛtam
For the span of two kalās they drink it; and the remaining portion of his kalā, flowing forth on the night of Amāvāsyā (new moon), becomes the amṛta—the nectar of their own radiance—born from the rays.
Suta Goswami
It links sacred time (kāla) and lunar phases (kalā, Amāvāsyā) to the flow of sustaining nectar, implying that Shiva-pūjā aligned with tithi—especially Amāvāsyā—harmonizes the worshipper with the cosmic ordinance upheld by Pati (Shiva).
Though Soma is named, the teaching reflects Shiva-tattva as the regulator of kāla and kalā: the measured outflow and remainder indicate an ordered cosmic economy where time and nourishment function under the Supreme Lord’s governance.
Tithi-based observance—especially Amāvāsyā discipline (vrata, japa, and Shiva-archana)—is implied, emphasizing purification of the pashu (individual soul) by aligning practice with cosmic rhythms rather than random timing.