Retrograde periods for Mercury, Venus, Mars, Jupiter and Saturn. Rahu and Ketu are always retrograde by convention.
4 retrograde periods in 1971
20 days in Dhanu
24 days in Mesha
24 days in Simha
20 days in Vrishchika
1 retrograde period in 1971
123 days in Vrishchika
1 retrograde period in 1971
60 days in Makara
1 retrograde period in 1971
134 days in Vrishabha
Rahu and Ketu are the lunar nodes and are always Vakri (retrograde). They move backwards through the zodiac at roughly 1.5° per month and change Rashi only once every ~18 months.
