Vimshottari Mahadasha

Vimsa means twenty, Uttara means after. Vimsa+Uttara is Vimshottara and it means "twenty after". If we don't specify the latter part (20 after what?), then the default is 100. So it defaults to "Vimshottari Shata" or "20 after 100", i.e. 120. 

• Only 27 Nakshatras are considered in Vimshottari Dasha. 

• All 9 planets (including Rahu-Ketu) are considered in Vimshottari Dasha.

• Life span of human being is considered 120 year in Kaliyuga. Hence a planet’s Dasha comes only once in a lifetime of each person. 

Planet	Nakshatra
Sun	Kritika	U. Phalguni	U. Shada
Moon	Rohini	Hasta	Shravana
Mars	Mrigashira	Chitra	Dhanishta
Rahu	Ardra	Swati	Shatataraka
Jupiter	Punarvasu	Vishakha	P. Bhadrapada
Saturn	Pushya	Anuradha	U. Bhadrapada
Mercury	Ashlesha	Jyeshtha	Revati
Ketu	Magha	Moola	Ashwini
Venus	P. Phalguni	P. Shada	Bharani

• Commencing from Kritika the Dasha Lord would be Sun, Moon, Mars, Rahu, Jupiter, Saturn, Mercury, Ketu and Venus in the three cycles of Nakshatras, so each Planet will rule 3 Nakshatras.

• Span of Dasha: 120 year are distributed amongst the 9 planets as

• The number of Nakshatra between Kritika and the Birth Nakshatra (counting from Kritika) be divided by 9, the remainder will indicate the Dasha Lord at the time of birth by counting from Sun in the sequence said above. 

• If the count comes to zero then consider the planet before Sun (which is Venus)

• With the help of the above example from page No. 2, will find out the Dasha Lord for the native from example: the birth Nakshatra of the native is Pushya, so

• Step – 1 # Finding Dasha Lord
• From Kritika to Pushya the count comes to 06. 
• Dasha Lord = No. of Nakshatra between Kritika & birth Nakshatra                                                            09
               

According to the sequence of Planets in Vimshottari Dasha the 6th planet from Sun is Saturn. Hence the Vimshottari Dasha of the native at the time of birth was of Saturn. 

Now we have to find out the balance Dasha period at the time of birth of the native. there are 2 types to calculate the Balance Dasha  

• Step – 2 # Balance of Dasha:

We found Saturn as Dasha Lord for the native, now we need to calculate the remaining period of Dasha to be experienced by the native or lets say we have to see the period of Saturn Dasha already completed at the time of birth if the native. 

• To calculate we need below details in Pala & planet Dasha yrs.

                Bhabhoga = 55 Ghati & 25 Pala = 3325 Pala
                Bhayaata = 50 Ghati & 12 Pala = 3012.5 Pala
                Planet Dasha years (Lord) = 19

• There are 3 lairs to calculate the expired years, months and days

         a) Expired years of Dasha = 

                    Bhayaata x Planet Dasha years

                               Bhabhoga

                = 3,012 x 19    = 57,237    = 17 years

3325    3325

        b) Expired months of Dasha = 

      Remainder from Expired year division x 12 months 

                            Bhabhoga

                     = 712 x 12      = 8544    = 2 months

    3325           3325

        c) Expired days of Dasha = 

      Remainder from Expired months division x 30 days 

                                       Bhabhoga

    

                     = 1894 x 30    = 56,820   = 17 days

                            3325            3325

By this 3 lair working we calculated the expired Dasha of the native. Total Dasha of Saturn is of 19 years out of which the expired Dasha of Saturn for the native is 17 years 2 months and 17 days. 

So Dasha yet to experience = Number of years of planet Dasha – Expired Dasha period

 = 19 years – 17 years 2 months and 17 days. 

 = 01 year 09 month 13 days Dasha yet to experience

Retrograde Planet Mahadasha

Effects:

• Any Retrograde malefic planet in 2nd house from Ascendant lord which also has a malefic behind it (in its 12th house) – the Antardasha of these two malefic in the Mahadasha of the Ascendant lord will set some serious disease. 
• If 9th house lord is a retrograde planet then native gets disappointed about ethics, principals, beliefs and values or starts finding realities in these things. This transformation is bound to happen in case of retrograde planet.

(These are my study notes referred from Brihat Parashara Hora Shastra)