In Vedic Astrology, the Sanskrit term “Dasha” means the planetary period. The planetary period provides information to astrologers when the good or bad effects are produced as per Planets placement in Zodiac sign, House, Yoga formed and Aspects. This Dasha system is very unique to Vedic Astrology and nowhere it has found. As per Sage Parashara, there are forty-two Dasha system. However, out of forty-two, there are two very famous and popular namely “VIMSHOTARI” (120 years) and “ASHTOTTARI (108 years). In our analysis, we will be using the VIMSHOTTARI dash system.
Each Mahadasha is also sub-divided into Planetary periods called Antardasha or Bhukti and each Antardasha is subdivided into the Planetary period called Pratyantardadsha. For example, if the first Antardasha of Venus is Venus/Venus, the second is Venus/Sun, the third is Venus/Moon and so on. This subdivision gives more insight into what events are going to occur and when.
So let’s understand what is Mahadasha, Antardasha, and Pratyantardasha?
For example, In any country there is a Central government, then State Government and also County/district level government and for any individual who is staying in any district/county, he/she has to follow the decision made by all the three government. In the same manner, on any individual, all the planets ruled by Mahadasha, Antardasha, and Pratyantardasha give their effect.
The divisional longitude of each of the 27 nakshatras beginning with Ashwini and ending with Revati is 13 degrees and 20 minutes further divided into four quarters or padas. Each of the nine planets presides over a set of three nakshatras situated on the zodiac at a trine from each other. The commencing Dasha or mahadasha at the time of birth will be that of the lord of the nakshatra in which the Moon is placed, which particular nakshatra is known as the “Janma nakshatra”. If the Moon is in Taurus in Mrigsira the first Dasha will be of Mars, the second will be that of Rahu and so on.

The data of each planets give results as per their position in Zodiac sign/constellation, house, aspects and any yoga formed by planets. Using data system astrologer can come to know about Health, wealth, happiness, activity, age and the general well-being of human beings. However, here are the general effects of Mahadasha
Ketu – 7 years
Favorable: If Ketu is favorably placed one devotes time and energy to the perusal of philosophy texts and engages in worship, derives much income from the practice of medicine, enjoy domestic comforts and luxuries, good luck and freedom from disease.
Unfavorable: But if Ketu is ill-placed one may suffer intense pain of body and anguish of mind, accidents, wounds, and fever have low company and suffer bad consequences through them.
Venus – 20 years
Favorable: If Venus is strong and favorably placed one may acquire things of art and pleasure, co-operates with others reciprocally in a harmonious manner and gains, falls in love, gets married, love and affection for spouse increases, begets daughters, rise due to the patronage or favor of some lady and well-wishers.
Unfavorable: But if Venus is weak and afflicted one suffers from ill-health, contracts urinary or venereal diseases, low sexual prowess, monetary loss, lack of favors and support, disharmony at home and outside and earns a bad name.
Sun – 6 years
Favorable: If the Sun is strong and favorably placed the soul will feel strong, one may make efforts for self-realization, live splendidly, travel far and wide, engage in strife or hostility that yields good dividend, rise in position and status, gains through trading, and benefits from father or father will benefit.
Unfavorable: If the Sun is weak and afflicted one may feel inner weakness, suffer a decline in physical and mental prowess, health troubles, demotion in rank and status, the displeasure of the government, trading losses and suffer at the hands of father or his father may suffer ill-health or die.
Moon – 10 years
Favorable: If the Moon is strong and favorably placed one may have a cheerful heart, a happy and vigorous mind, facial luster increases, enjoys subtle pleasures and comforts, obtains a good job or rises in status, gains money and favors and pays homage to gods.
Unfavorable: If the Moon is weak and afflicted one suffers from ill-health, lethargy and indolence, loss of job or demotion, loss from or quarrel with women and mother may fall ill or die.
Mars – 7 years
Favorable: If Mars is strong and favorably placed one may gain from or through brothers, earn favor from persons wielding authority, enter into or promotion in military, para-military or police service, acquires landed property and other valuables, enjoys good health, exhibits optimism, daring and persistence.
Unfavorable: If Mars is weak and afflicted one may suffer from fall, wounds, deterioration of blood, at the hands of a magistrate, become quarrelsome, exchanges hot words, earns enmities, hates and litigates.
Rahu – 18 years
Favorable: If Rahu is favorable one may gain ruling powers or rise in governmental favors by resorting to falsehoods, tricks and cunning, earn and gain wealth through unscrupulous means, changes place of residence.
Unfavorable: But if Rahu is unfavorable one suffers very many losses, suffers from snake-bite, an aberration of the mind, hallucinations and illusions, asthma, eczema, etc. It is the worst mahadasha for education or career which may be broken or disrupted.
Jupiter – 16 years
Favorable: If Jupiter is strong, well-placed and forms good yogas one is inclined to learning and increase of knowledge; if it comes in middle age it confers wealth and bestows sons, one leads a comfortable life, one goes on pilgrimage and has auspicious celebrations, and in old age bestows grandsons, better income and finances.
Unfavorable: If Jupiter is weak and afflicted one gives up education, suffers from failures, poverty and many miseries including fall from position and ill-health, commits evil deeds, becomes frustrated, sons or grandsons may also suffer.
Saturn – 19 years
Favorable: If Saturn is favorable one rises in service by own strenuous efforts and hard work, derives benefits from things signified by Saturn and gains a legacy.
Unfavorable: But if Saturn is unfavorable one may suffer from diseases due to malnutrition, poverty, litigation, etc.; quarrels and disputes with elders, deaths in the family or of near ones, impediments and obstacles in the path of progress and miserable life due to distress all around.
Mercury – 17 years
Favorable: If Mercury is strong and favorable one devotes time and energy to studies, writing, etc.; remains active, engage in commerce or politics or diplomacy, gains through dealings with others and trade, enjoys company of friends, peace and tranquillity and lives in comfortable surroundings.
Unfavorable: But if Mercury is weak and afflicted one may suffer from a nervous disease, a bad liver, loss due to bad friends and relations, due to their own dishonesty and of others, defamation and the like.