AMAYA · SCIENCE AND ACCURACY
Check us tonight. Here is every command you need.
We compute the sky ourselves, we publish how wrong we are, and we say which of our own numbers go soft. A stranger with a terminal can verify all three in one evening, and this page exists so that they can.
what we compute ourselves
Over nine thousand lines, and no ephemeris library in production
Solar and lunar longitude by Meeus, the full chapter 47 lunar series, Lahiri ayanāṃśa and the shift between tropical and sidereal coordinates, sunrise and sunset for an exact latitude, lunar days, elected hours and the whole natal apparatus.
Over nine thousand lines of our own astronomical code across forty files. No third-party ephemeris library runs in production. One MIT-licensed package, astronomy-engine, sits in our development tooling and is used by a single test that checks our lunar-node series against it.
the error we publish
Against NASA's JPL Horizons, on eight dates
Eight dates spread from 2024 to 2028, nineteen checks in all. Our Moon lands within 0.011° and our Sun within 0.009°; ayanāṃśa stays inside 0.0001°. On the boundary of a lunar day, 0.011° is about one minute.
The check runs inside our build and fails if the next change makes the accuracy worse. Measured 17 September 2026.
how to repeat it
The command, whole
Take our positions for a date, take the JPL Horizons positions for the same instant, and subtract. Two minutes of work and no permission from us.
- 01
Ask JPL Horizons for the geocentric apparent longitude of the Moon and the Sun at the instant you choose, in the ecliptic of date.
- 02
Ask AMAYA for the same instant: the day page prints the tropical longitude beside the sidereal one, and the difference between them is the ayanāṃśa we used.
- 03
Subtract. Anything past 0.02° on the Moon is a number we would want to hear about, and the address is on the press page.
where our limits are
What a rough birth time really costs you
A birth time known to the hour moves the Moon by up to half a degree and drags everything fine-grained with it: the houses, the divisional charts, the exact turn of a daśā. The Sun, Mars, Jupiter, Venus and Saturn barely move at all.
So AMAYA marks what went soft and declines to name your houses rather than rounding a guess into confidence. We would rather lose a screen of content than hand you a number that quietly is not true.
what we do not claim
the score that can go against us
A mechanism built to be able to refute us
Every evening a person marks whether the day's reading held. Those marks build a percentage that belongs to them and that we keep against ourselves.
If the number is bad we will be the first to see it, and it is stored as two halves of one row: the morning forecast and the evening confirmation. We have not found another product in this category that keeps a score it can lose.
From question to result