सूर्यरथनिर्णयः (चन्द्रस्य पक्षवृद्धिक्षयविधानम्)
वृद्धिक्षयौ वै पक्षादौ षोडश्यां शशिनः स्मृतौ एवं सूर्यनिमित्तैषा पक्षवृद्धिर्निशाकरे
vṛddhikṣayau vai pakṣādau ṣoḍaśyāṃ śaśinaḥ smṛtau evaṃ sūryanimittaiṣā pakṣavṛddhirniśākare
Wachsen und Schwinden, so heißt es, treten zu Beginn der Mondhälfte und am sechzehnten Tithi des Mondes auf. So wird, mit der Sonne als bestimmender Ursache, dieses Anwachsen der Mondhälfte im Nachtbereiter, dem Mond, begründet.
Suta Goswami (narrating to the sages of Naimisharanya)
It grounds Shiva-puja timing in kala (sacred time): understanding waxing/waning tithis helps choose auspicious vrata and abhisheka days, aligning worship with the cosmic order governed through Sun–Moon measures.
By implying that cosmic regulation (kala-niyati) operates through luminaries, it points to Pati (Shiva) as the transcendent Lord of time, while Sun and Moon function as instruments within His ordered manifestation.
Muhurta- and tithi-based observance—planning vrata, japa, and Linga-abhisheka in harmony with paksha progression; for Pashupata-oriented sadhana, this supports disciplined practice through regulated time.