Three Levels of Dasha Timing
Vimshottari has three nested levels: Mahadasha (MD, major period), Antardasha (AD, sub-period), and Pratyantar Dasha (PD, sub-sub-period). Each uses a proportional calculation based on the parent period's length.
Mahadasha (Mahabuktis)
Mahadasha is the outermost level. A single mahadasha lasts from 6 years (Sun) to 20 years (Venus). We have already covered how to calculate the starting mahadasha (from Moon's nakshatra) and its balance.
Antardasha (Bhukti) — The Formula
Within each mahadasha, the nine planets take turns ruling sub-periods. The length of each antardasha is calculated proportionally:
Antardasha Formula:
Antardasha Duration = (Mahadasha Lord's Years × Antardasha Lord's Years) / 120
Example: In Moon Mahadasha (10 years), the Mars Antardasha has length (10 × 7) / 120 = 70/120 ≈ 0.583 years ≈ 7 months.
Antardasha Sequence: Always the same 9-planet order, regardless of which mahadasha lord is running. Within Moon MD, the antadashas are: Moon, Mars, Rahu, Jupiter, Saturn, Mercury, Ketu, Venus, Sun (in that order).
Pratyantar Dasha (PD) — The Second Sub-Level
Within each antardasha, the nine planets rule even finer sub-sub-periods. The formula is similar:
Pratyantar Dasha Formula:
Pratyantar Duration = (Antardasha Lord's Years × Pratyantar Lord's Years) / 120
Example: In Moon MD / Mars AD (0.583 years ≈ 7 months), the Jupiter Pratyantar has length (7 × 16) / 120 = 112/120 ≈ 0.933 years ≈ 11 months.
Worked Example: Calculate Mahadasha–Antardasha–Pratyantar Periods
Scenario: Native born with Moon in Rohini (Moon MD, balance 4 years). Calculate Moon MD completely, including first three antadashas and their pratyantars.
Moon Mahadasha (MD): 4 years balance (from birth)
Start: Birth | End: Birth + 4 years
Antardasha 1 (Moon in Moon MD):
Duration = (10 × 10) / 120 = 100/120 = 0.833 years ≈ 10 months
→ Pratyantar 1 (Moon in Moon/Moon):
Duration = (10 × 10) / 120 = 0.833 years ≈ 10 months (but capped by parent)
This gets complex; typically the first pratyantar lasts roughly 1–2 months in this case.
Antardasha 2 (Mars in Moon MD):
Duration = (10 × 7) / 120 = 70/120 ≈ 0.583 years ≈ 7 months
Mars/Moon AD runs from ~10 months to ~17 months after birth.
Antardasha 3 (Rahu in Moon MD):
Duration = (10 × 18) / 120 = 180/120 = 1.5 years = 18 months
Key Points on Dasha Arithmetic
- 1. Always use the formula: (Parent Years × Child Years) / 120
- 2. The sequence is fixed: Ketu, Venus, Sun, Moon, Mars, Rahu, Jupiter, Saturn, Mercury, repeating.
- 3. Rounding: Use decimal years or convert to months/days as needed. 0.5 years ≈ 6 months.
- 4. Validation: All nine antadashas within a mahadasha should sum to the mahadasha duration.
- 5. Modern tools: Hand-calculating dasha periods is tedious. Most practitioners use software or tables.