The Saptamsha chart, D-7, is the fifth of the sixteen divisional charts, formed by dividing each sign into seven parts. It signifies children and progeny, the capacity to have offspring, their well-being, and the wider theme of creative continuation and legacy. It echoes the fifth house of the birth chart, which governs children and creativity. An astrologer consults the D-7 for questions of fertility, the number and fortunes of children, and the continuation of the line. The chart is one of the shodashavarga, the set of harmonic subdivisions through which jyotisha magnifies each department of a single nativity. These are the interpretive conventions of the tradition; the divisional charts are a mathematical method for extracting focused readings from the one set of planetary positions recorded at the birth moment.
The rule alternates by the odd or even parity of the sign being divided: in the six odd signs the seven Saptamsha divisions are counted starting from the sign itself, while in the six even signs the count instead begins from the seventh sign onward. Because the pattern flips at every sign rather than running in one direction across the whole zodiac, two planets a single sign apart, one in an odd sign and one in the even sign following it, can land in quite different, unrelated parts of the D-7 even though their birth positions were close together, a sensitivity to the odd or even parity of the base sign that several of the finer vargas share with the Saptamsha.