सूर्यरथनिर्णयः (चन्द्रस्य पक्षवृद्धिक्षयविधानम्)
वृद्धिक्षयौ वै पक्षादौ षोडश्यां शशिनः स्मृतौ एवं सूर्यनिमित्तैषा पक्षवृद्धिर्निशाकरे
vṛddhikṣayau vai pakṣādau ṣoḍaśyāṃ śaśinaḥ smṛtau evaṃ sūryanimittaiṣā pakṣavṛddhirniśākare
月之增与减,被说是在半月之初与第十六日(tithi)发生。由是以太阳为决定之因,这半月的增长便在“造夜者”——月亮之中得以成立。
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.