BASICS OF VEDIC ASTROLOGY

LESSON 1- I
VIMSHOTTARI DASHAS AND ANTARDASHAS
We understand that the planets give good or bad results basing on the position of planets in exalted houses, own houses etc., and various afflictions. But when, the results will be experienced by the native, is also essential. A glance at the birth chart for a few moments gives abundant information about his past present and future. The timing of the incident can be known with the help of Vimshottari Dasa system. In old astrological texts, some other systems for timing of incidents viz. ashtottari dasa, yogini dasa etc were explained. But Vimshottari system devised by Sage Parashara is widely accepted in Vedic Astrology. In practice also, Vimshottari Dasa system proved the best. Vimshottari means 120. The total period of nine planets is 120 years. The period controlled by each planet is given in Lesson 1 C, which is known as Maha Dasa or the main period of the planet. The planetary periods are divided into 5 divisions called Mahadasa, Antardasa, Vidasa, Sookshma Dasa and Prana Dasa. It is cumbersome process to go deep into Vidasa, Sookshma Dasa and Prana Dasa systems. Let us confine primarily to Maha Dasa and Antardasa. A table showing the periods of Mahadasa and Antardasa in respect of each planet is given below.
The formula for calculation of Antardasa is simple and the following example clarifies the same.
If we want to calculate Moon antardasa in Sun Mahadasa, take the periods of Mahadasas of both the planets i.e. 6 years of Sun and 10 years of Moon. Multiply the same which gives 60. Then divide the figure by 120 (i.e. total number of years of all planets), which gives ½, i.e. 6 months. Another example to calculate Rahu antardasa in Mars Mahadasa. The period of Rahu is 18 years and Mars is 7 years. Multiplication of both the numbers give 126. Divide it by 120 i.e. total number of years of all planets, which gives 126/120, which gives 1 year 0 months and 18 days. All antardasas in each Mahadasa should be calculated in the same manner.
There is a shortcut method for calculation of Antardasas. Let us calculate Rahu antardasa in Mars Mahadasa. Multiply both the numbers as shown above i.e. 18 years multiplied by 7, which gives 126. Now from 126, consider the first two digits represent months i.e. 12 months or say one year. Now consider the third digit 6 and simply multiply with 3 which give 18. Hence, the antardasa of Mars in Rahu Mahadasa is 1 year 0 months and 18 days.
Another example Moon Antardasa in Sun Mahadasa. 6X10=60. Take the first digit 6 and consider it as months. Multiply the 3rd digit 0 with 3, which gives 0. Hence, Moon Antardasa in Sun Mahadasa would be 0 years 6 months and 0 days or simply 6 months.
However, a ready reckoner is also given below for information.