How it actually works
Exact math, named and checkable.
Astro Ratan makes a specific claim — 'reads your exact chart, computed to the degree.' Here is exactly what that means, so you can judge it instead of taking it on faith.
The zodiac
Sidereal, on the Lahiri ayanamsa
Vedic astrology anchors the zodiac to the actual fixed stars rather than to the seasons — the sidereal zodiac, as opposed to the tropical zodiac Western astrology uses. The gap between the two is called the ayanamsa, and it exists because Earth's axis slowly wobbles (precession), drifting the two reference points apart by roughly one degree every 72 years.
Astro Ratan uses the Lahiri ayanamsa (also called Chitrapaksha) — the sidereal standard adopted by India's Calendar Reform Committee in the 1950s, and the one behind the government's own Rashtriya Panchang. It is not a single fixed number: it grows by roughly fifty arcseconds a year, so every chart recomputes the current value rather than reusing an old table. For the full history of why this correction exists and how it's defined, see ayanamsa, explained.
The planets
Swiss Ephemeris, to the degree
Every planetary position — the exact degree, minute and second, not a rounded sign — is computed on the Swiss Ephemeris, a high-precision astronomical dataset used broadly across serious astrological and astronomical software. Positions are calculated for your specific birth date, time and place, then corrected to the sidereal zodiac with the ayanamsa above.
This is the layer that separates a real chart from a generic one: a chart computed this way changes with every input, down to the minute of birth. A service that gives the same reading regardless of exact birth time is not reading your chart at that level of precision.
The houses
Bhava Chalit — real unequal cusps, not whole-sign
The twelve houses of a chart can be divided more than one way. The simplest method — whole sign — treats each house as exactly one 30° zodiac sign, starting from whichever sign the ascendant falls in. It is easy to compute, which is why many free calculators use it.
Astro Ratan instead computes Bhava Chalit, the classical system attributed to the astronomer Sripathi: genuine unequal house cusps derived from the ascendant's precise degree, rather than a house boundary that only ever falls exactly at a sign's edge. Because the cusps are unequal, a planet sitting near the edge of a sign can fall into a different house than the simpler whole-sign method would place it in — which is exactly the kind of precision an exact birth time makes possible, and an approximate one (see below) makes uncertain.
The timing
Vimshottari Dasha, timed from your Moon
Astro Ratan reads planetary periods — dashas — through the Vimshottari system, the 120-year cycle of nine fixed planetary periods classically described in Brihat Parashara Hora Shastra. Which period you were born into, and how much of it had already elapsed at birth, is set by the Moon's exact position within its birth nakshatra — which is why an accurate birth time matters as much for timing as it does for the ascendant. The full mechanics are covered in Vimshottari Dasha, explained.
Honest limits
What an approximate birth time changes
If you don't know your exact birth time, Astro Ratan still casts a chart — using noon as a stand-in — but records that fact explicitly rather than treating an unverified time as confirmed. Your Moon sign and planetary sign positions are generally still correct regardless of birth time, since the Moon moves through a sign over roughly two and a half days. Your ascendant and house placements, on the other hand, genuinely depend on the exact minute of birth — the ascendant itself changes roughly every two hours — so those specific parts of a reading should be treated as approximate until a real birth time is available.
