The 120-year planetary time-period system · the most-used predictive tool in Vedic astrology.
A daśā (दशा) is a planetary time-period — a window during which a specific planet (graha) acts as the "period-lord" and shapes life events through its natal placement.
Vimśottarī ("of 120") allocates 120 years across 9 planets in a fixed cyclic order. The starting point is determined by the Moon's nakṣatra at birth.
| # | Planet | Sanskrit | Years |
|---|---|---|---|
| 1 | Ketu | केतु | 7 years |
| 2 | Venus | शुक्र | 20 years |
| 3 | Sun | सूर्य | 6 years |
| 4 | Moon | चन्द्र | 10 years |
| 5 | Mars | मंगल | 7 years |
| 6 | Rāhu | राहु | 18 years |
| 7 | Jupiter | गुरु | 16 years |
| 8 | Saturn | शनि | 19 years |
| 9 | Mercury | बुध | 17 years |
| TOTAL | 120 years | ||
The cycle then repeats. Most people experience all 9 mahā-daśās exactly once.
The top-level. Lasts 6-20 years. Major life-shape · which planet is in charge.
Each mahā-daśā subdivides into 9 antar-daśās proportional to the same 120-year ratio. So Saturn's 19-year mahā-daśā has Saturn-Saturn (3 years), Saturn-Mercury (2.7 years), etc.
Each antar-daśā subdivides into 9 pratyantar-daśās. This is the level at which specific events get triggered. Marriage, layoff, childbirth, accident usually correspond to a specific pratyantar combination.
Two people born on the same day can be in completely different mahā-daśās. The starting period depends on which 1/27th of the Moon's path (the nakṣatra) you were born under.
Janma-nakṣatra of Aśvinī, Maghā, Mūla = born in Ketu mahā-daśā · 7 years. Bharaṇī, Pūrva-phālgunī, Pūrva-aṣāḍhā = born in Venus mahā-daśā · 20 years. And so on for all 27 nakṣatras.
This determines your entire 120-year sequence. Two people born hours apart with different nakṣatras run completely different daśā timelines.
What a daśā does depends on:
This is why generic daśā readings ("Saturn period = bad") are wrong. YOUR Saturn period depends on where YOUR Saturn sits and what it does in YOUR chart.