In short
SachAstro's numbers come from its own calculation engine, which uses NASA JPL's DE440 planetary data, and from written rules that we publish and label as tradition wherever they are tradition. Every guide is drafted with AI help, checked against our guardrails before it is published, and corrected openly when something is wrong.
Where the numbers come from
All planet positions are computed by our own engine from NASA JPL's DE440 ephemeris, the planetary data set used for spacecraft navigation, through the open-source Skyfield library. An AI model never calculates a position, a time or a score.
- Zodiac: sidereal, with the Lahiri ayanamsa.
- Sunrise and sunset: the moment the Sun's upper edge touches the horizon, with standard atmospheric refraction.
- Moonrise and moonset: the centre of the Moon's disc at the horizon, seen from the city itself.
- Tithi: the Moon's distance ahead of the Sun, in steps of 12 degrees.
- Vaar (weekday): counted from local sunrise, not midnight.
- Times: Indian Standard Time, rounded to the nearest minute.
Before publishing festival times, we checked our Diwali and Chhath results for 10 cities against a leading public panchang on 29 October 2026. Every value was within 2 minutes.
The rules we follow
Kundli milan follows the SachAstro Matching Standard v1 (MS-1.0), which we wrote down so anyone can check a result:
- The raw guna milan score out of 36 comes first.
- Each traditional exception is shown as its own line, with the text it is attributed to.
- Manglik is checked three ways: from the lagna, the Moon and Venus.
- A result is marked provisional unless both birth times are exact.
- The bands (24 and above, 18 to 23.5, below 18) are labelled as convention, because we found no classical verse that fixes them.
Where traditions or software disagree, we say which choice we made. Festival muhurat follow the traditional rule for each festival, for example Pradosh Kaal with Vrishabha lagna on Amavasya for Diwali Lakshmi Puja.
How the palm scan works
The palm scan runs on your phone. The photo is read there and is never uploaded or stored. The lines are traced and measured, and each one is shown with what tradition says about it. The scan is for ages 16 and up. Where the photo is not clear enough, the scan says so instead of guessing.
How we write and check these guides
- Drafting. Guides are drafted with AI help by the SachAstro editorial team, from our own engine's output, our published rules and named classical texts.
- Checks before publishing. An automated checker reviews every guide against our guardrails: no fear language, no guarantees, no predictions about health, death, legal cases, pregnancy or a child's gender, no names of people or other companies, and no number without a source or our own engine behind it.
- People. A person on our team reads a sample of published guides every week. We only say a page was checked by our team when a person actually checked it.
- Dates. The "last updated" date changes only when the content changes.
What we do not claim
- Astrology, muhurat and palm reading are traditions. We present them as tradition, not as proven science.
- A muhurat is a traditional rule for timing, not a guarantee of any result.
- A guna milan score describes a traditional comparison. It does not predict whether a marriage will be happy.
- We never read lifespan, health, illness, court cases, pregnancy or the gender of a child from a chart or a palm.
- Nothing here is medical, legal or financial advice.
Corrections
If you find a mistake, write to hello@sachastro.com with the page and what looks wrong. We check it, fix it if we got it wrong, and update the page's date.