Vimshottari dasha calculator
Vimshottari dasha is how Vedic astrology puts dates on a chart. It hands each of the nine grahas a period of fixed length across a 120 year cycle, and the period running at any given date is read as the backdrop to what happens then. This works out your whole sequence from birth, down to the pratyantardasha, and marks where you are in it now.
How the cycle is anchored
The order of the nine periods never changes: Ketu 7 years, Venus 20, Sun 6, Moon 10, Mars 7, Rahu 18, Jupiter 16, Saturn 19, Mercury 17. What changes from person to person is where you enter that loop and how much of the first period had already run before you were born.
Both are decided by the Moon. The nakshatra it occupied at your birth names the lord your cycle opens with, and how far it had already travelled through that nakshatra sets the balance remaining. Everything after that is arithmetic, which is why the whole timeline can be computed in one pass rather than period by period.
Why a rounded birth time ruins a dasha timeline
This is the part worth being blunt about. The Moon moves about half a degree an hour, and a nakshatra is 13 degrees 20 minutes wide, so a small error in the birth time becomes a visible error in where your cycle starts. That error does not stay small: it applies to every period boundary in the timeline, and it compounds the further out you look.
A birth time wrong by ten minutes will typically move period start and end dates by months. If you are using dasha to make sense of something that already happened, or to time something you are planning, a rounded hospital time is not a small compromise, it is the difference between a reading that lines up and one that does not.
Reading a period properly
A mahadasha on its own is too coarse to explain a particular year. The convention is to read the combination: the mahadasha lord sets the theme, the antardasha lord inside it narrows the subject, and the pratyantardasha narrows the window further. That is why the timeline above opens into three levels rather than listing nine long periods.
The relationship between those lords in your own chart matters as much as their names, so a timeline is a starting point rather than a reading. Draw the full kundli to see where each lord actually sits, and the glossary defines the terms used here.
Takes about 10 minutes.
Vimshottari dasha, answered
What is Vimshottari dasha?
Vimshottari dasha is the main timing system in Vedic astrology, a 120 year cycle that gives each of the nine grahas a period of fixed length: Ketu 7 years, Venus 20, Sun 6, Moon 10, Mars 7, Rahu 18, Jupiter 16, Saturn 19 and Mercury 17. The period running at a given date is read as the backdrop to what happens then.
How is my starting dasha decided?
By the exact position of the Moon at your birth. The Moon's nakshatra names the lord your cycle opens with, and how far it had already travelled through that nakshatra decides how much of the first period had already elapsed before you were born. That leftover portion is the dasa balance at birth.
What is the difference between mahadasha and antardasha?
A mahadasha is one of the nine major periods, lasting six to twenty years. Each mahadasha is divided into nine antardashas, also called bhuktis, in the same planetary order, and each antardasha divides again into pratyantardashas. Timing an event usually means reading the combination running on that date rather than the mahadasha alone.
Why does my dasha need an exact birth time?
Because the whole sequence is anchored to where the Moon sat at one instant, and the Moon moves about half a degree an hour. A birth time wrong by ten minutes shifts every period start and end date in the timeline, often by months, and the further into the future you look the further the error has compounded.
How far ahead does this calculate?
The full 120 year cycle from birth, subdivided down to the pratyantardasha level, with the periods running today marked. You can open any mahadasha to see its antardashas rather than only the one you are in now.