How this calculator works — and why apps disagree
Vimshottari dasha assigns each life a repeating cycle of nine planetary periods totalling 120 years. Your entry point into the cycle is fixed by the moon's exact sidereal position at birth: its nakshatra names the first dasha lord, and the fraction of the nakshatra already travelled sets how much of that period remained at birth. Everything after that is fixed arithmetic — Ketu 7, Venus 20, Sun 6, Moon 10, Mars 7, Rahu 18, Jupiter 16, Saturn 19, Mercury 17.
When two apps disagree about your dasha, the cause is almost always the input, not the tradition: a different ayanamsa, a rounded birth time (the moon moves about 13° per day), or table-lookup moon positions instead of computed ones. This tool computes the moon's longitude with a real astronomical ephemeris and the Lahiri ayanamsa, in your own browser — which is also why we don't need to collect your data to show you the result.
What the tool deliberately does not do is tell you your period is "dangerous" and sell you the cure. A dasha is a season, not a sentence — our methodology page spells out that line, in writing.