Variations
We always compute the fraction left at birth in the first dasa based on the fraction of the constellation occupied by Moon, that is yet to be traversed by Moon. However, we need not always take the lord of Moon’s constellation as the planet ruling the first dasa. We can take the lord of the 4th, 5th or 8th constellation from Moon’s constellation to start the first dasa. These 3 stars are called kshema, utpanna and adhana stars.
The 4th star from Moon’s star is Uttarabhadrapada owned by Saturn. Using the 4th star to start Vimsottari dasa, we get the dasa sequence as — Saturn, Mercury, Ketu, Venus etc. Dasa lengths are the same as before, but the part of Saturn dasa left at birth is 19 x 0.32125 = 6.10375 years. Then Mercury dasa is for 17 years, Ketu dasa is for 7 years and so on.
In the same example, the 5th star from Moon’s star is Revathi owned by Mercury. Using the 5th star to start Vimsottari dasa, we get the dasa sequence as — Mercury, Ketu, Venus, Sun etc. Mercury dasa left at birth is 17 x 0.32125 = 5.46125 years. Then Ketu dasa is for 7 years, Venus dasa is for 20 years and so on.
In the same example, the 8th star from Moon’s star is Krittika owned by Sun. Using the 8th star to start Vimsottari dasa, we get the dasa sequence as — Sun, Moon, Mars, Rahu etc. Sun dasa left at birth is 6 x 0.32125 = 1.9275 years. Then Moon dasa is for 10 years, Mars dasa is for 7 years and so on.
Dasa from Lagna
Some authorities have also recommended Vimsottari dasa from the longitude of lagna instead of Moon. In practice, this will give better results only when lagna is considerably more powerful than Moon.
Using Dasa Variations
If the sign containing the 5th star from Moon is stronger than the sign containing Moon, Vimsottari dasa started from utpanna star may be preferred for general results. If the 5th star spans across 2 signs, take the sign containing the same quarter as occupied by Moon in birthstar. If Moon is in Makha 3rd pada (quarter), for example, 5th star is Chitra and it starts in Virgo and ends in Libra. So we should take the 3rd quarter of Chitra and we then get Libra. So Leo’s strength should be compared to Libra’s.
How do we know which sign is stronger? There are no clear guidelines in the literature to compare the strengths. A sign aspected by Jupiter and occupied by more planets may be taken to be stronger. We can also use known events to see which dasa is working better.
Vimsottari dasa started from the 4th and 8th stars is used mainly for the purposes of longevity determination. Look at the signs containing Moon and these 2 stars and find the strongest sign. Here a sign aspected by marakas and malefics becomes stronger. Start Vimsottari dasa from the star in the strongest of these 3 signs and use it in longevity analysis. If Moon is in Makha 3rd pada in Leo, 4th and 8th stars are Hasta (Virgo) and Anuradha (Scorpio). We should compare the strengths of Leo, Virgo and Scorpio.