Budha Dasha

The Mercury Mahadasha is the period of Budha in the Vimshottari dasha, lasting seventeen years, and it closes the fixed sequence before the cycle begins again at Ketu. It follows Saturn. As the significator of intellect, speech, commerce, and skill, Mercury in its dasha is traditionally read as a season favouring learning, communication, trade, and dexterity, its benefic or mixed results shaped by the company Mercury keeps and its placement in the birth chart, for Mercury takes on the nature of the planets it joins. The dasha a person is born into is set by the nakshatra of the natal Moon. These are the interpretive conventions of the tradition; the Vimshottari system is a mathematical timing scheme keyed to the Moon's birth nakshatra, its nine periods together spanning one hundred and twenty years.

Mercury's seventeen years closes out the fixed sequence before it returns to Ketu and begins again, and because Mercury is classically held to take on the nature of whatever planet it is conjunct or aspected by, more than any of the other eight grahas, its mahadasha is traditionally read as the least fixed in character of the nine, its outcome depending heavily on natal placement rather than on any settled Mercurial theme in the way Sun or Saturn periods carry a more constant signature. The full hundred-and-twenty-year Vimshottari cycle repeating from Ketu again after Mercury means a single human lifetime, on the system's own hundred-and-twenty-year premise, is expected to complete at most one full pass through all nine mahadashas, with the specific starting point set, as throughout this system, by the birth Moon's nakshatra.

This period runs seventeen years of the 120 that the Vimshottari cycle divides among the nine grahas, and a life enters it at birth if the Moon stood in one of its lord's three nakshatras, Ashlesha, Jyeshtha and Revati.

The order of the nine periods is fixed and does not vary: Ketu, Venus, Sun, Moon, Mars, Rahu, Jupiter, Saturn, Mercury, and then Ketu again. It is the same order in which the nine grahas own the twenty-seven nakshatras, running three times through the list, which is what ties the dasha sequence to the Moon's position at birth. The nakshatra the Moon occupied gives the period a life begins in, and the fraction of that nakshatra already traversed gives how much of the period has already elapsed.

Each major period is subdivided in the same order and in the same proportions. A mahadasha is divided into nine antardashas, each running for the same fraction of it that its lord's own period bears to the whole 120 years, and the subdivision can be carried further into pratyantardashas and beyond. That is how the system produces timing fine enough to be tested: a combination in a chart is expected to show during the period and subperiod of the planets that form it.

Mercury holds seventeen years and closes the list before it returns to Ketu. Seven, twenty, six, ten, seven, eighteen, sixteen, nineteen and seventeen sum to exactly 120, and the completeness of that sum is the internal check that the scheme is being stated correctly.