Dashas

A period ruled by one graha. Dashas are Jyotish's timing system and its clearest structural difference from Western astrology, which has no equivalent built in. Dozens of dasha schemes exist; Vimshottari is the one in general use.

The standard dasha system, running 120 years in nine unequal periods: Ketu 7, Venus 20, Sun 6, Moon 10, Mars 7, Rahu 18, Jupiter 16, Saturn 19, Mercury 17. Which period you are born into, and how far through it, is set by the Moon's exact position within its nakshatra — so a wrong birth time shifts your entire life timeline.

A sub-period inside a dasha, also called bhukti. Each mahadasha is divided among all nine grahas in the same 120-year proportions, so a 20-year Venus mahadasha contains a Venus–Venus antardasha of 3 years 4 months, and so on down.

A main dasha period, as against its subdivisions. In Vimshottari the shortest is the Sun's at 6 years and the longest Venus's at 20, so most people live through only six or seven mahadashas.

The roughly seven-and-a-half years in which Saturn transits the sign before the Moon sign, the Moon sign itself, and the sign after. It follows arithmetically from Saturn taking about 2½ years per sign, so it happens to everyone, about three times in a long life. It is the most feared and most oversold period in popular Indian astrology.