Where the traditions disagree, and which convention Jyotishya uses

Why this matters

Astrology texts and modern software don't all use the same rules. Where they differ, Jyotishya picks one documented convention, applies it exactly and says which one it is. These are the main choices.

Janma tara

Jyotishya scores the Janma tara, the day the Moon returns to the birth nakshatra, as 0. Drik Panchang rates it not good, and B. V. Raman's Muhurtha calls it ordinarily unfavourable, with exceptions. Scoring it −1 would lower many Vedic days by one point.

The Moon's 2nd, 5th and 9th houses

Phaladeepika (26.4) lists houses 1, 3, 6, 7, 10 and 11 from the natal Moon as good. Verse 26.12 names 4, 8 and 12 as adverse, and also 2, 5 and 9. Jyotishya scores 2, 5 and 9 as 0, between the two verses; 4 and 12 as −1; and 8, Chandrashtama, as −2.

Noon or sunrise

Panchangs name the nakshatra in force at sunrise and give its end time. Jyotishya reads each day at local noon, a single moment that needs no sunrise calculation for a place. The Moon crosses about a quarter of a nakshatra in six hours, so on roughly one day in four the noon nakshatra differs from the sunrise one.

One score from two rules

Tradition uses tara bala and the Moon-from-Moon rule as two filters that should both be good. Adding them into a single score is Jyotishya's own arithmetic, shown in every day's working.

Western transit orbs

Typical transit orbs are 1 to 3° (Astrodienst uses 1°). Jyotishya uses 4.5 to 6° for the Moon because one noon reading has to stand for the whole day: 6° is about 11 hours of the Moon's motion. Ptolemy counts the Moon among the benefics; Jyotishya scores the transiting Moon's conjunction with the natal Moon as 0.

BaZi

Day and hour use local mean solar time, with the day pillar changing at midnight. For a birth between 23:00 and midnight, the hour stem is taken from the next day's stem, the split Zi hour, on which both main schools agree for the stem. The day rating uses fixed signs and ignores Day Master strength, a recognised simplification. The element count uses main elements only, without hidden stems.

Other conventions

Sidereal zodiac with the Lahiri ayanamsa; whole-sign houses; the mean lunar node; 365.25-day dasha years; the seven classical planets plus Rahu and Ketu, with no outer planets.