How we calculate गणना की विधि
Janmaxar follows the conventions most Indian families and Jyotishis use. They are listed here so that you can compare our results with other software.
Zodiac and ayanamsha
The sidereal zodiac, with the Lahiri (Chitrapaksha) ayanamsha.
Planet positions
Positions are calculated with astronomy-engine, accurate to about one arcminute, and tested against the Swiss Ephemeris on more than 500 reference charts.
Rahu and Ketu
The mean node, with Ketu exactly opposite Rahu.
Houses
Whole-sign houses counted from the Lagna, drawn as a North Indian chart. Without a birth time, the chart is cast from the Moon (Chandra Lagna), and everything that needs the Lagna is left out.
Navamsha
The D9 divides each sign into nine parts in the standard Parashari way.
Vimshottari dasha
Counted from the Moon’s nakshatra at birth, with a year of 365.25 days. Near the edge of a period, dates can differ by a few days from software that uses another year length.
Panchang
Tithi, yoga and karana come from the Sun and Moon at birth. The vara changes at local sunrise (the upper edge of the Sun, allowing for refraction), so a birth before sunrise belongs to the previous day. Months are amanta, ending at the new moon.
Time and place
Local time is converted with the IANA time-zone database, including historical offsets. Place names and coordinates come from GeoNames.
Yogas and doshas
Each yoga and dosha lists the exact conditions we check and its classical source. Kaal Sarp, Pitra and Grahan doshas are later ideas, not found in BPHS or Phaladeepika, and are marked as such.
If your results differ
Small differences from other software usually come from the ayanamsha, the node or the dasha year. If something still looks wrong, check the birth time and place first: a few minutes can change the Lagna.