Lamp of the Determination of Lunar Days

Lunar Day 8 Sacred Text 5 On the anniversaries of the Manus Manvadi specific days considered the start of the reigns of various progenitor figures in Hindu cosmology, during eclipses of the sun or moon, on the anniversaries of the four Ages Yugadi, or during the astrological period of Vaidhriti: Determination

The prescribed rites should be performed at that exact moment; in these cases, the technical rule of "completeness" the requirement for a lunar day to span a specific duration like sunrise to sunrise does not apply. || 6 ||

In the sacrifices of the New Moon Darsha and Full Moon Purnamasa, and similarly in rites for the gods, the cessation of eating should likewise occur only at the specific time prescribed by the lunar calendar. || 7 ||
When breaking a fast Parana, or performing rites for one's birth star Janma Nakshatra, as well as for oil baths and immersion in water—even for activities like brushing the teeth, sexual union, or sleep—the timing must follow exactly what is specified in the Sacred Texts Shastra for those specific lunar days. || 8 ||

Thus ends the determination of the Instantaneous Lunar Day original: "Tatkalika Tithi"; refers to a lunar day defined by the exact moment an event occurs rather than its duration at sunrise. Now begins the determination of the Second Lunar Day.

If the day begins on the previous day and continues through the rising of the sun... || 9 ||
Regarding the fitness for a fast Upavasa starting from sunrise: if the lunar day exists on the previous day and continues for three Muhurtas a unit of time approximately 48 minutes long; three muhurtas equals roughly 2 hours and 24 minutes after sunrise on the following day, the great scholar Madhava Madhavacharya declared that for scriptural fasts, the first day should be chosen. || 10 || When the Second Lunar Day Dvitiya exists at the rising of the sun and continues afterward...