Vimshottari Dasha

The most important and widely used dasha system is the Vimshottari dasha, which is a cycle of 120 years based on the maximum possible life span for an individual.Each of the seven planets and the two lunar nodes (making the nine navagraha) has its own period or mahadasha in the cycle.The Vimshottari dasha is linked to the system of nakshatras or lunar mansions by the fact that each of the navagraha is the lord (or ruler) of three of the twenty seven nakshatras (3 x 9),which together with the position of the moon,determine how the system operates.
The order and times of the mahadashas are shown in the following table:

Graha	Mahadasha
Mercury	17 years
Ketu (South node)	7 years
Venus	20 years
Sun	6 years
Moon	10 years
Mars	7 years
Rahu (North node)	18 years
Jupiter	16 years
Saturn	19 years

Note:- Rashis where Ketu is considered debilitated are Gemini & Taurus & is have exalted in Rahu,Scorpio & Sagittarius.