Every compatibility test on earth asks you for someone first. This one doesn't. Give us your birth details and we'll give you the thirty-six short stretches of the year the people best matched to your chart were born in — ranked from your own birth star (the star your moon was in when you were born). Your first window is free.
“You're compatible with Gemini” is a whole month of the calendar and about six hundred million people. That isn't a claim, it's a horoscope. We give you dates — stretches of four to fifteen days — because that is the smallest honest unit the maths supports.
From someone's birthday alone we can already read whether you'd be easy together, whether you'd clash, how the sex is, and whether you bring each other luck. That is about half of a real match — and it is the heavier half.
The other half needs their birth time and where they were born: which one of you gets their way, whether you actually like talking to each other, and whether you make each other's life better or harder.
So somebody born in your number one window can still land lower than somebody from a weaker one — it comes down to the time. That is also why these windows are ranked and rated instead of given a percentage: a number here would look like the match score, and it would be lying to you. The windows tell you where to look. A real check tells you what you found.
The sun crosses one nakshatra — a lunar mansion, 13°20′ of the sidereal zodiac — in about thirteen days. There are twenty-seven of them, and nine straddle the line between two rashis (signs), which is why the year divides into thirty-six distinct windows rather than twenty-seven.
Each window is scored twice. Half comes from the classical star tests run between your janma nakshatra (your moon's birth star) and the star the candidate's sun occupies: Nadi (constitution, 8 points), Gana (temperament, 6), Yoni (instinct, 4) and Tara (timing, 3) — the twenty-one points of Ashtakoot that depend on the stars alone. The remaining fifteen — Bhakut (moon-sign fit), Graha Maitri (friendship), Vashya (sway) and Varna (outlook) — need both moon signs, which a birthday cannot supply, so the other half of the score stands in for them from your moon, sun and rising.
Positions are computed to Swiss-ephemeris precision on the Lahiri ayanamsa, the standard sidereal correction. The four star tests are the same code that runs the paid 36-point Guna Milan report, so the two can never disagree about the same pair.
The sun spends about two weeks in each of twenty-seven “birth stars” — a finer grid than the twelve signs everybody knows. Your own birth star is the anchor. We read every other stretch of the year against it.
Four old tests decide it: whether your constitutions clash, whether you'd get annoyed at the same things, whether you run at the same pace, and the old body-and-instinct match. They are not weighted the same — and the cards show you which ones matter more.
You give four things: your date, time and city of birth, and your name. Seconds later your dashboard opens on your ranked dates. The first one is free and it is the whole card, not a teaser.
Don't know your exact birth time? Start without it. It sharpens the birth star, and you can add it later.