Ruleset 2026.10.2 · generated 2026-10-21 · Swiss Ephemeris files
How Jyothisham works and how accurate it is
Jyothisham works out the sky with standard astronomy, then reads it with classical jyotish rules. This page shows how closely the astronomy matches independent references, and where every rule comes from. Every number here is produced by the same checks the engine runs before each release.
Panchang against Drik Panchang
12 cities (Ahmedabad, Bengaluru, Chennai, Guwahati, Hyderabad, Kolkata, London, Mumbai, New Delhi, New York, Thiruvananthapuram, Varanasi) on 12 dates of 2026, read from Drik Panchang day pages (drikpanchang.com), Lahiri ayanamsa on 2026-10-21. Drik shows times to the minute, so differences under a minute are expected.
| Time | Days | Typical gap (min) | Largest gap (min) |
|---|---|---|---|
| Sunrise | 144 | 0.49 | 1.02 |
| Sunset | 144 | 0.52 | 1.12 |
| Tithi ends | 143 | 0.53 | 1.18 |
| Nakshatra ends | 130 | 0.33 | 0.72 |
| Yoga ends | 141 | 0.32 | 0.95 |
| Karana ends | 144 | 0.59 | 1.18 |
| Rahu Kaal starts | 144 | 0.54 | 1.08 |
| Moonrise | 133 | 0.57 | 1.03 |
| Moonset | 144 | 0.52 | 1.05 |
| Abhijit starts | 120 | 0.47 | 1.08 |
Planets against an independent library
Positions compared with PyEphem (independent astronomy library) at random moments across 1950–2050. One arc-minute is 60 arc-seconds; a nakshatra pada is 12,000.
| Planet | Samples | Typical (″) | Largest (″) |
|---|---|---|---|
| Sun | 50 | 19.66 | 39.33 |
| Moon | 50 | 10.63 | 26.94 |
| Mercury | 50 | 13.9 | 37.56 |
| Venus | 50 | 16.02 | 38.43 |
| Mars | 50 | 12.35 | 39.75 |
| Jupiter | 50 | 14.24 | 38.66 |
| Saturn | 50 | 8.4 | 35.28 |
New and full moons against NASA
7 eclipse-season new and full moons from the NASA eclipse catalogue (Espenak): largest gap 0.33 minutes, typical 0.15 minutes.
Guna Milan against published examples
| Example | Published | Jyothisham | Kootas that match |
|---|---|---|---|
| Prokerala sample report | 20 | 20.0 | 8 / 8 |
| Prokerala API example | 28 | 28.0 | 8 / 8 |
| FreeAstrologyAPI | 15.0 | 15.0 | 8 / 8 |
| AstrologyAPI detailed report | 28 | 28.0 | 8 / 8 |
| DivineAPI | 28 | 28.0 | 8 / 8 |
| RoxyAPI | 28 | 28.0 | 8 / 8 |
How often each kind of day appears
Across 100 sample charts, every 14 days of 2026: 18% favorable, 63% steady, 19% take care. For one person it varies: favorable days ranged from 0% to 41% (median 19%), and 20 of 100 people had under 5% favorable days, because slow planets sit in the same signs for months. Jyothisham does not invent good days to even this out.
Conventions
| Zodiac | Sidereal, Lahiri (Chitrapaksha) ayanamsa |
| Houses | Whole sign, counted from the lagna |
| Rahu and Ketu | Mean lunar node; Ketu exactly opposite |
| Sunrise and sunset | Upper edge of the Sun on the horizon, standard refraction |
| Moonrise and moonset | Centre of the Moon, no refraction (Drik Panchang's convention) |
| Hindu day | Sunrise to the next sunrise |
| Lunar month | Amanta (new moon to new moon); adhik when no solar ingress falls inside it |
| Dasha | Vimshottari, 365.25-day years |
| Transits | Counted from the birth Moon, Phaladeepika ch. 26, with vedha |
| Guna Milan | Ashtakoot 36 points; cancelled doshas are reported, points are not restored |
| Muhurat | Muhurta Chintamani and Drik Panchang exclusions; Rahu Kaal, Yamaganda and Gulika always avoided |
What this page does not claim
It shows that Jyothisham's astronomy and arithmetic are correct and where each rule comes from. It does not claim that astrology predicts events. Jyothisham never predicts death, illness, accidents or divorce, never sells remedies or gemstones, and points to a professional for health, money and legal questions.
For astrologers: the full rule table
Transits (gochara) with vedha
| ID | Planet | Good houses | Vedha | Weight | Areas | Source |
|---|---|---|---|---|---|---|
| G-SUN | Sun | 3, 6, 10, 11 | 3→9, 6→12, 10→4, 11→5 | 1.0 | career, health | Phaladeepika 26 |
| G-MOON | Moon | 1, 3, 6, 7, 10, 11 | 1→5, 3→9, 6→12, 7→2, 10→4, 11→8 | 1.5 | career, money, relationships, health | Phaladeepika 26 |
| G-MARS | Mars | 3, 6, 11 | 3→12, 6→9, 11→5 | 1.0 | health, career | Phaladeepika 26 |
| G-MERC | Mercury | 2, 4, 6, 8, 10, 11 | 2→5, 4→3, 6→9, 8→1, 10→8, 11→12 | 1.0 | career, money | Phaladeepika 26 |
| G-JUP | Jupiter | 2, 5, 7, 9, 11 | 2→12, 5→4, 7→3, 9→10, 11→8 | 2.0 | money, relationships, career | Phaladeepika 26 |
| G-VEN | Venus | 1, 2, 3, 4, 5, 8, 9, 11, 12 | 1→8, 2→7, 3→1, 4→10, 5→9, 8→5, 9→11, 11→3, 12→6 | 1.0 | relationships, money | Phaladeepika 26 |
| G-SAT | Saturn | 3, 6, 11 | 3→12, 6→9, 11→5 | 2.0 | career, health | Phaladeepika 26 |
| G-RAHU | Rahu | 3, 6, 11 | 3→12, 6→9, 11→5 | 1.0 | career, money | Phaladeepika 26 |
| G-KETU | Ketu | 3, 6, 11 | 3→12, 6→9, 11→5 | 0.5 | health | Phaladeepika 26 |
No vedha between Saturn and Sun, Mercury and Moon. Vipareeta vedha is on (a convention, not stated in Phaladeepika 26).
Special rules
| ID | Weight | Areas | Source |
|---|---|---|---|
| S-CHANDRASHTAMA | 2.0 | career, money, relationships, health | Muhurta Chintamani; Moon 8th from natal Moon |
| S-TARABALA | 0.5 | career, money, relationships, health | Muhurta Chintamani; tara count from janma nakshatra |
| L-SAT-8 | 1.0 | health | Saturn transiting the 8th from lagna |
| S-SADESATI | 0.5 | career | Saturn in the 12th, 1st or 2nd from the natal Moon |
Guna Milan kootas
| Koota | Points | Source |
|---|---|---|
| varna | 1 | Muhurta Chintamani, vivaha prakarana; varna by Moon sign |
| vashya | 2 | Muhurta Chintamani; vashya by Moon sign |
| tara | 3 | Muhurta Chintamani; tara counted both ways |
| yoni | 4 | Muhurta Chintamani; yoni by nakshatra |
| graha_maitri | 5 | BPHS ch. 3 natural friendship of the Moon-sign lords |
| gana | 6 | Muhurta Chintamani; gana by nakshatra |
| bhakoot | 7 | Muhurta Chintamani; rashi koota |
| nadi | 8 | Muhurta Chintamani; nadi by nakshatra |
Muhurat events
| Event | Source |
|---|---|
| Marriage | Muhurta Chintamani, vivaha prakarana 13, 55; Drik Panchang |
| Griha pravesh | Muhurta Chintamani, griha pravesha prakarana 1–5; Drik Panchang |
| Vehicle purchase | Muhurta Chintamani, nakshatra prakarana 18; Drik Panchang |
| Starting a business | Muhurta Chintamani, nakshatra prakarana 17; B.V. Raman |
| Travel | Muhurta Chintamani, yatra prakarana 8–12 |
| Naming ceremony | Muhurta Chintamani, samskara prakarana 11; Drik Panchang |