The main dasha system of the tradition and the one nearly every reading uses: it divides the life into nine planetary periods, in the order Ketu, Venus, Sun, Moon, Mars, Rahu, Jupiter, Saturn, Mercury, whose lengths are 7, 20, 6, 10, 7, 18, 16, 19 and 17 years.
Meaning
Vimshottari allots a hundred and twenty years among the nine grahas, and the period in force at any moment is the one that colours everything else in the chart. The sequence is counted from the Moon's nakshatra at birth, so the balance of the first period depends on how far the Moon had travelled through its nakshatra; each period is then divided into sub-periods (antardasha or bhukti) in the same order beginning with the period lord, and those again into pratyantardashas.