Vimshottari Dasha: 120-Year Sequence and Birth Balance
Learn all nine Vimshottari lengths, the Moon-nakshatra starting rule and remaining birth balance. Keep model years distinct from calendar conventions.
Overview
Vimshottari is a nine-ruler timing cycle with 120 model years. In the Moon-nakshatra method taught here, the natal Moon’s nakshatra lord determines the first mahadasha, and the Moon’s untraversed fraction determines how much remains at birth.
At a glance
- Cycle
- 120 model years; not a lifespan prediction
- Sequence
- Ketu → Venus → Sun → Moon → Mars → Rahu → Jupiter → Saturn → Mercury
- Lengths in that order
- 7, 20, 6, 10, 7, 18, 16, 19, 17 years
- Year convention
- Must be stated before producing calendar dates
What is the Vimshottari order?
The sequence repeats after Mercury back to Ketu. The nine full lengths sum to 120: 7 + 20 + 6 + 10 + 7 + 18 + 16 + 19 + 17. The first period in a person’s displayed timeline need not be Ketu because the birth Moon selects the entry point.
Rao §§16.1–16.2 explains this standard entry through the Moon’s nakshatra; later sections discuss variations. Do not present a different start as an implemented switch without evidence. The 120-year cycle is a system parameter, not a prediction of longevity.
How is the first period’s remaining balance found?
Each of the 27 equal nakshatras spans 13°20′, or 800 arcminutes. Divide the untraversed arc by 800 and multiply by the full length of its lord. Use the unrounded sidereal Moon position and the declared ayanamsa, not only its sign name.
For an invented Moon halfway through Moon-ruled Rohini, half of the full 10-year Moon period remains: 5 model years. It does not restart as ten years at birth. The preceding five model years also matter when locating the active antardasha.
Why might two calculators give different end dates?
Rao §16.2 explicitly discusses competing year conventions, including 360 days and solar-year choices. The locally reviewed OpenFate policy uses 365.25 days per dasha year. This is a declared calculation convention, not a universal agreement among schools or a claim about the current deployment.
Compare year basis, lunar longitude, birth timestamp and boundary handling before calling a date wrong. If birth-time uncertainty changes the Moon’s nakshatra or the target interval, retain both candidates. Continue to the current-dasha guide for interval arithmetic rather than forecasting an outcome from the ruler alone.
Sources and editorial basis
- P. V. R. Narasimha Rao: Vedic Astrology — An Integrated ApproachRao, Vedic Astrology: An Integrated Approach. §§16.1–16.2 / Table 38, pp. 209–211: 120-year total, nine lengths, Moon-nakshatra start, remaining birth balance and disputed year conventions; §16.3, p. 212: subperiod context. These passages document named traditional methods, not scientific validity. Examples are synthetic, not verified birth observations.A named practitioner’s introduction to Jyotish. Used for terminology and a stated method, not universal school agreement or scientific validation. The added March 18, 2010 note describes changed views; it does not establish a fully revised 2010 edition.
- OpenFate Editorial MethodologyOpenFate Editorial Methodology, stable sections #editorial-principles, #editorial-workflow, #editorial-ai, and #editorial-context. Used for the calculation/interpretation and evidence-boundary policy.OpenFate separates deterministic chart calculation, traditional interpretation, and modern editorial explanation.
- OpenFate Vedic implementation: local source review, 2026-09-08Read-only source review on 2026-09-08: openfate/app/modules/vedic/logic/policy.ts, VEDIC_ENGINE_POLICY (vedic-policy-1.1.0): Vimshottari only and 365.25-day years; math.ts, horaSign and computeVargaSigns: named D2 Sun/Leo and Moon/Cancer mapping plus D6/D9/D10/D24. This verifies the local declared implementation, not current production or alternate-method UI support.An editorial review of local policy and calculation source files, not an independently accessible publication or proof of the deployed version. Implementation limitations and discrepancies remain separate from traditional arithmetic.