Dasha systems compared: Vimshottari, Yogini, Chara
Vimshottari is one of several dasha systems. Others include Ashtottari, Yogini, Chara (Jaimini) and Narayana dashas. Each uses a different rule for the order and length of periods.
What it is
Ashtottari is a 108-year cycle that starts from the Rahu dasha for some nakshatras. Yogini is a 36-year cycle of eight yoginis. Chara dashas are sign-based and come from the Jaimini tradition, and Narayana dashas are also sign-based.
How it is worked out or read
The traditions do not agree on which system to use for which chart. Vimshottari is the most common, and this site computes only Vimshottari.
Where it appears on this site
The dasha tool computes Vimshottari only. The yogini dasha article explains one of the others.
The main systems in brief
Several dasha systems are described in the Jyotish literature. Vimshottari is a 120-year cycle set from the Moon's nakshatra. Ashtottari is a 108-year cycle that begins with Rahu for some nakshatras and runs through the eight grahas other than Ketu. Yogini is a 36-year cycle of eight yoginis. Chara dashas are sign-based and come from the Jaimini tradition. Each system has its own rules for the starting point, the order and the length, and each has its own followers.
Choosing among them is a matter of tradition and teacher. Many practitioners use Vimshottari for most purposes and turn to other systems for specific questions. The reader who meets a system not described here should check its starting rule and its length table before using it, since the systems are not interchangeable.
What makes Vimshottari the most used
Vimshottari has a simple and widely repeated arithmetic, a clear link to the nakshatras, and a long history of use in the commentaries. These features make it the default in most printed almanacs and in the software that most readers encounter. Its simplicity is also a strength for checking: a reader can reproduce the timeline by hand, as this site's dasha article shows, which is harder with the more complex systems.
Its popularity is not proof that it is the only correct system. The classical texts describe several methods, and the reader should be aware that the choice shapes the timeline. A careful reader states which system is used whenever a dasha is described.
Using more than one system
Some traditions combine dasha systems, comparing the Vimshottari timeline with an Ashtottari or a Yogini timeline to see whether they agree on an important period. Agreement is read as a stronger indication, and disagreement as a reason to look more closely. This practice requires careful calculation and sources for each system, and the site does not yet compute the others.
Choosing a system for a question
Practitioners often choose the system to fit the question. A general timeline for life direction may use Vimshottari, while a finer question about a shorter stretch may use a shorter cycle. This is a matter of practice and not a rule in every text. A reader should say which system was chosen and why, so that the choice can be judged rather than assumed.
Consistency matters more than the particular choice. A reader who uses one system throughout a reading, with a clear reason, can give a coherent account. A reader who switches systems mid-reading without comment will confuse the picture.