Chandra Dasha

The Moon Mahadasha is the period of Chandra in the Vimshottari dasha, lasting ten years. In the fixed sequence it follows the Sun and precedes Mars. As the significator of the mind, the emotions, the mother, and the public, the Moon in its dasha is traditionally read as a time when feeling, domestic life, the relationship with the mother, and one's public standing become prominent, the results shaped by the Moon's condition, waxing or waning, well or ill placed, in the birth chart. The dasha sequence a person enters at birth is fixed by the nakshatra of the natal Moon itself. These are the interpretive conventions of the tradition; the Vimshottari system is a timing method that assigns each of the nine grahas a period of set length in a set order across the hundred-and-twenty-year cycle.

Because the whole Vimshottari calculation is keyed to the Moon's nakshatra, it depends on a sidereal zodiac and therefore on an ayanamsha, the measured offset between the sidereal and tropical zero points produced by the precession of the equinoxes. Different ayanamsha values, Lahiri, Raman, and Krishnamurti among the most used, shift nakshatra boundaries by a degree or so relative to one another, and a birth Moon lying close to a nakshatra boundary can fall under a different dasha lord, and begin the Vimshottari sequence at a different mahadasha, depending on which ayanamsha the astrologer has chosen. This is one of the more consequential places where a seemingly small technical choice, invisible in the finished chart, can change the entire timeline of predicted periods that follows from it.

This period runs ten 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, Rohini, Hasta and Shravana.

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.

The Moon's period is ten years. The Moon has a double role in this system, since it is both one of the nine period lords and the body whose position determines where the whole sequence starts, which is why an accurate lunar longitude matters more here than in most other astrological methods.