Matsya Purana — Soma
कालः कुहूसिनीवाल्योः समुद्धो द्विलवः स्मृतः अर्कनिर्मण्डले सोमे पर्वकालः कलाः स्मृताः //
kālaḥ kuhūsinīvālyoḥ samuddho dvilavaḥ smṛtaḥ arkanirmaṇḍale some parvakālaḥ kalāḥ smṛtāḥ //
Between the lunar phases called Kuhū and Sinīvālī, the interval known as a kāla is said to comprise two lavas. And when the Moon is within the Sun’s surrounding orb (the solar halo), that period is known as the parva-time; it is measured in kalās.
It does not describe Pralaya directly; it defines precise calendrical time-units and liminal “parva” periods used to regulate rites—knowledge that supports cosmic order (ṛta) rather than dissolution narratives.
It supports dharma through correct observance: kings and householders are expected to perform śrāddha, vrata, dāna, and public rituals at properly computed junction-times (parva), using standardized measures like lava and kalā.
Ritually, it highlights parva-time as a sensitive junction for ceremonies; in applied Vastu/temple practice, such parva- and kalā-based calculations inform muhurta selection for foundation-laying, installation (pratiṣṭhā), and consecration rites.