Narada Purana — Purva Bhaga, Shloka 172
Jyotiṣa-śāstra Saṅgraha: Threefold Division, Gaṇita Methods, Muhūrta, and Planetary Reckoning
वक्रर्त्वोर्गतियोगामं गम्येतीते दिनादिकम् । खनत्यासंस्कृतौव्वेषूदक्साम्येन्येंतरं युतिः ॥ १७२ ॥
vakrartvorgatiyogāmaṃ gamyetīte dinādikam | khanatyāsaṃskṛtauvveṣūdaksāmyenyeṃtaraṃ yutiḥ || 172 ||
By the conjunction of a planet’s motion with its season of retrograde movement, one should determine the elapsed and remaining measures of time—days and the like. In computations involving excavation and other unrefined operations, the correction is obtained by taking the mean in accordance with the equality of the directions (the quarters).
Sanatkumara (in instruction to Narada)
Vrata: none
Primary Rasa: shanta
Secondary Rasa: adbhuta
FAQs
It frames accurate time-reckoning as a dharmic discipline: understanding motion and time supports correct observance of vrata, worship timings, and orderly life conducive to moksha.
Bhakti practice depends on proper sacred timing (days, observances, fasts). The verse underlines that devotion is strengthened when rituals and vows are aligned with correct calendrical and astral calculations.
Vedanga Jyotisha—using planetary motion (including retrograde periods) to compute elapsed/remaining time units, and applying a ‘mean/equalization’ correction method in rough or uncorrected calculations.