The Drekkana is the third divisional chart: each sign is cut into three parts of 10 degrees, and those parts fall in the sign itself, in the 5th from it and in the 9th from it. Brihat Parashara Hora Shastra ch. 6 assigns the D3 to siblings and courage, and it is read alongside the 3rd house of the birth chart.
Three parts of 10 degrees fill a sign, and the Parashari rule sends them to the sign's own trine: the first decanate stays in the sign, the second goes to the 5th from it, and the third to the 9th. A planet at 3 degrees of Aries stays in Aries, at 15 degrees it moves to Leo, and at 25 degrees to Sagittarius.
Because the trine of a sign shares its element, every D3 placement stays within the same element as the original sign. That is a structural feature of this varga and not of the others, and it is the reason the D3 is sometimes described as the chart that redistributes a sign within its own nature.
The D3 has more published constructions than almost any other division, and AstroZivi ships four rather than choosing one silently. The Parashari trine-forward scheme above is the default. The Jagannath scheme, following Sanjay Rath, starts the trine by modality. The Somanath scheme runs odd signs forward and even signs in reverse and is used for readings of kama. The Parivritti scheme treats the thirty-six decanates as one continuous cycle.
This page computes the Parashari default; the full divisional-charts tool exposes all four with the note attached to each. Where the sources disagree, the choice belongs to the reader, and the site's job is to say clearly which arithmetic produced the chart on the screen.
The classical assignment is siblings and courage, and a reading pairs the D3 with the 3rd bhava of the birth chart, its lord and Mars as the natural significator of brothers and of initiative. The division adds resolution to that reading; it does not replace it.
A 10 degree decanate is the widest part of any of the divisions on this site apart from the D2, so the D3 is the most forgiving of an uncertain birth time: the ascendant takes about forty minutes to cross one. That makes it usable on a chart whose time is approximate, where a D60 would be meaningless.
Brihat Parashara Hora Shastra ch. 6 assigns the D3 to siblings and courage. It is read alongside the 3rd house of the birth chart, its lord and Mars, the natural significator of brothers and of initiative.
Divide each sign into three parts of 10 degrees. In the Parashari scheme the first stays in the sign, the second maps to the 5th sign from it and the third to the 9th, so every placement remains within the same trine and therefore the same element.
Because the sources genuinely differ. AstroZivi computes four: Parashari trine-forward as the default, Jagannath which starts the trine by modality, Somanath which runs odd signs forward and even signs in reverse, and Parivritti which treats the thirty-six decanates as a continuous cycle.
Less than most vargas. A decanate is 10 degrees wide and the ascendant takes about forty minutes to cross one, so the D3 remains usable when the birth time is approximate - unlike the D60, whose parts are covered in about two minutes.
Yes. Drekkana, dreshkana and decanate all name the same 10 degree third of a sign. The Vedic and Western traditions divide the sign identically here, though they map the resulting third to a sign by different rules.
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