A clock, not a verdict
A dasha is a planet period. It is a set of years when one graha sets the tone of your life. The most used system is Vimshottari. It puts all nine grahas into a 120-year cycle. Where your cycle starts depends on your janma nakshatra. So no two people walk it the same way.
A dasha is not a prediction. It is a theme. It is what this part of your life keeps asking you to learn.
The 120-year Vimshottari cycle
- Ketu7y
- Venus ♀20y
- Sun ☉6y
- Moon ☽10y
- Mars ♂7y
- Rahu18y
- Jupiter ♃16y
- Saturn ♄19y
- Mercury ☿17y
Periods inside periods
Each mahadasha is a big period. It splits into nine antardashas, or small periods. They follow the same order of planets, just shorter. A 20-year Venus mahadasha starts with Venus-Venus. Then Venus-Sun. Then Venus-Moon. And so on. Old readings go even deeper. But the big and small periods tell most of the story.
This is why some years feel very different from the years before. The small period changed, so the flavour of the theme changed too.
How to read yours
Just knowing "I am in Saturn mahadasha" does not tell you much. What matters is how Saturn sits in your chart. Which houses does it rule? Where is it placed? What does it look at? A well-placed Saturn period often brings the most solid years of a life. Slow, steady, and quietly good.