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In Jaimini System, whenever we talk about dasha, it implies dasha of sign like Aries, Taurus, Gemini … Pisces. In this system, Chara Dasha has its own importance as it is unconditional dasha which is applicable for all horoscopes.  Chara Dasha begins from sign rising in the Lagna. Suppose Aries sign is rising in the Lagna, first Mahadasha will be of Aries. Likewise, the sequence of Antara, Pratyantara etc will be in the same manner.  In a particular sign dasha first antaradasha, pratyantardasha etc will of that particular sign.

In Jaimini System the direction of Char Dasha is very important.  There are six signs which adopt direct direction when these are in Lagna.  These signs are Aries, Leo, Virgo, Libra, Aquarius and Pisces.  And rest six signs (Taurus, Gemini, Cancer, Scorpio, Sagittarius and Capricorn follow indirect direction.   

The pattern of the Char Dasha Sequences is as follows:

 

Lagna            Pattern of the Char Dasha

Aries: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, Pisces

Taurus: Aries, Pisces, Aquarius, Capricorn, Sagittarius, Scorpio, Libra, Virgo, Leo, Cancer, Gemini

Gemini: Gemini, Taurus, Aries, Pisces, Aquarius, Capricorn, Sagittarius, Scorpio, Libra, Virgo, Leo, Cancer

Cancer: Cancer, Gemini, Taurus, Aries, Pisces, Aquarius, Capricorn, Sagittarius, Scorpio, Libra, Virgo, Leo

Leo: Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, Pisces, Aries, Taurus, Gemini, Cancer

Virgo: Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, Pisces, Aries, Taurus, Gemini, Cancer, Leo

Libra: Libra, Scorpio, Sagittarius, Capricorn, Aquarius, Pisces, Aries, Taurus, Gemini, Cancer, Leo, Virgo

Scorpio: Scorpio, Libra, Virgo, Leo, Cancer, Gemini, Taurus, Aries, Pisces, Aquarius, Capricorn, Sagittarius

Sagittarius: Sagittarius, Scorpio, Libra, Virgo, Leo, Cancer, Gemini, Taurus, Aries, Pisces, Aquarius, Capricorn

Capricorn: Capricorn, Sagittarius, Scorpio, Libra, Virgo, Leo, Cancer, Gemini, Taurus, Aries, Pisces, Aquarius

Aquarius: Aquarius, Pisces, Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn

Pisces: Pisces, Aquarius, Capricorn, Sagittarius, Scorpio, Libra, Virgo, Leo, Cancer, Gemini, Taurus, Aries, Pisces

 

For determining the length of Mahadasha, there is concept of counting in forward and backward order for particular sign.  Once we determine the starting Chara Dasha of a Rashi, the duration is that Rashi dasha is assessed by counting in forward or backward as follows:

If a planet is in its own sign, it is assigned twelve years.

 

Lagna           Duration of the Char Dasha

Aries: Count Forward to Mars' location, then subtract 1

Taurus: Forward to Venus' location, then subtract 1

Gemini: Count forward to Mercury's location, then subtract 1

Cancer: Count backward to the Moon's location, then subtract 1

Leo: Count backward to the Sun's location, then subtract 1

Virgo: Count backward to Mercury's position, then subtract 1

Libra: Count forward to Venus' location, then subtract 1

Scorpio: Count forward to Mars' (or Ketu's) position, then subtract 1*

Sagittarius: Count forward to Jupiter's position, then subtract 1

Capricorn: Count backward to Saturn's position, then subtract 1

Aquarius: Count backward to Saturn's (or Rahu's) position, then subtract 1*

Pisces: Count backward to Jupiter's position,a.sun subtract 1

*If there are more planets in the sign in which Mars or Saturn sits, then the counting is done to this sign; if there are more planets in the sign in which Ketu or Rahu sits, the counting is done to that sign.

If Mars is in Scorpio, and Ketu is not, then, Ketu is selected. If Ketu is in Scorpio and Mars is not, then Mars is picked. If both are alone in signs, then determine which among Ketu or Mars is at higher degree. The planet at higher degree is the winner.

If both are at the same degree, then count to the planet at higher minute. If both are at higher minute, count to the sign with higher second. This same way of determining the winning planet, for terms of counting the number of years to be assigned to the sign in question, is to be used for Saturn and Rahu in the case of Aquarius.
 
The number which results from the counting (including the sign from which the counting starts) is then to subtract 1 from the total. This will give the Mahadasha in years.