Jyotirvidabharanam (Kalidasa) (1800) - Page 10

Now, with this verse, he explains the Civil Sāvana: a measurement of time based on the interval between two consecutive sunrises and Solar Saura: time based on the Sun’s transit through the zodiac measurements. By the movement of the celestial bodies (3), from the very rising of the sun original: "sūryasyodaya", it is produced; this is already well-known. The wise should calculate this clearly and manifest it; it is known as the Civil day at all times. "Daily" means day by day, what is called the True Daily Motion Sphutabhakti: the actual distance a planet travels in a single day, which varies slightly. What does this mean? It means the distance the Sun travels in its own path every day. That itself is remembered by the learned as the Sun’s day. It is said to have "seven rays" a traditional poetic epithet for the Sun and is called a day. Now, he speaks of the measurement of the year from that:

1 [addition] is the calculation here... 6 ||

With the movement of the sun in the sky, known by the wise, the Civil day is clearly defined by the true daily motion.

Always, this motion is remembered by the learned (5). A month consists of the number of days specified by its own measure.

By twelve months, a year is completed; the lunar month is always the day and night for the ancestors, starting from the dark and bright fortnights (6).

By these [thirty days], one's own year is formed. Here, the word "month" is used in the plural. Everywhere, the word "own" original: "sva" is used to show that just as thirty days of the Sun make a solar month, so too for the Gods Devas: celestial beings whose "day" equals one human year, thirty of their days make their month. This should be understood for all beings according to their own scales.

Now, he explains the Ancestral Paitrya: pertaining to the Pitṛs or Manes, the spirits of the ancestors measurement. For the ancestors, a Lunar Month Cāndramāsa: the period of 29.5 days between new moons constitutes one full day and night. Their day begins with the start of the Dark Fortnight Kṛṣṇapakṣa: the waning phase of the moon. It is traditionally understood that for the ancestors, the dark fortnight is their daytime, and the Bright Fortnight Śuklapakṣa: the waxing phase of the moon is their night. This is because when the Sun rises for them, it marks the start of their day. In the middle of the sky... The text here becomes highly technical, discussing the position of the sun relative to the moon's path to explain why the lunar phases correspond to the ancestors' day/night cycle. ...for the ancestors' day and night.