Lagna: the ascendant and the twelve houses
The lagna (लग्न), or ascendant, is the sign rising on the eastern horizon at the moment of birth. It is the starting point of the birth chart: in the whole-sign houses common in Jyotish, the lagna's sign is the 1st house, the next sign the 2nd, and so on.
Why the time matters
The whole zodiac rises over the eastern horizon in a day, so the lagna changes about every two hours on average. At Indian latitudes some signs rise in about an hour and a half and others take more than two and a half hours. A birth time off by twenty minutes can therefore move the ascendant into the next sign. The place matters too, because the horizon depends on latitude and longitude. That is why My kundli shows no ascendant when no birth time is given.
The twelve houses
| House | Traditional themes |
|---|---|
| 1 | self, body, temperament |
| 2 | wealth, family, speech |
| 3 | courage, siblings, effort |
| 4 | home, mother, property |
| 5 | children, intelligence, speculation |
| 6 | rivals, illness, service, debt |
| 7 | partner, partnerships, trade |
| 8 | longevity, sudden events, hidden matters |
| 9 | fortune, dharma, teachers |
| 10 | career, status, action |
| 11 | gains, income, networks |
| 12 | losses, expenses, foreign lands, liberation |
Houses 1, 4, 7 and 10 are kendras (angles), 1, 5 and 9 trikonas (trines, the most fortunate) and 6, 8 and 12 dusthanas (difficult houses). The ruler of the lagna's sign, the lagna lord, is treated as the chart's own planet.
Three starting points
A chart can be read from three "first houses": the lagna itself, the Moon's sign (Chandra lagna) and the Sun's sign (Surya lagna). Transits (Gochar) are traditionally counted from the Moon, which is useful when the birth time is unknown: the Moon sign is usually the same all day, the lagna is not.
Stocks have ascendants too
Every stock kundli is cast for 09:15 IST in Mumbai on its NSE listing day, so it has an exact ascendant. Because NSE's opening time is the same every day, many companies listed in the same season share a lagna: the stars rise about four minutes earlier each day, so the sign rising at 09:15 changes roughly every month and goes round all twelve in a year.
Old birth times
Before 1972, clocks followed the Earth's rotation rather than atomic time. Our chart code reads older birth times that way, after a cross-check with the Swiss Ephemeris showed that ignoring this moved the ascendant by up to a quarter of a degree for births around 1900.
For learning and curiosity, not investment advice.