Shattrimsha-sama Dasha (also spelled Shattrimsa-sama or Shat-trimsat-sama, literally 'thirty-six equal') is a conditional udu (nakshatra-based) dasha of 36 years described in the Brihat Parashara Hora Shastra. The qualifier sama marks the family of dashas built on regular, ascending period lengths rather than the irregular shares of Vimshottari; here the eight grahas hold one through eight years in sequence. It is one of the conditional dashas Parashara reserves for charts that meet a specific birth condition, listed at the dasha hub with its siblings.

The eligibility rule is solar and lunar, keyed to the division of the day and the hora of the ascendant. Following the BPHS conditional-dasha chapter as translated by R. Santhanam, the system is preferred when birth occurs in daytime with the ascendant rising in the hora of Surya (the Sun), or in nighttime with the ascendant rising in the hora of Chandra (the Moon). The hora is the half-sign division: in odd signs the first half belongs to the Sun and the second to the Moon, and the order reverses in even signs. The day-from-Sun, night-from-Moon logic is the recurring marker of this dasha across sources, and it is what separates a qualifying chart from one read by the default Vimshottari.

The thirty-six years run across eight grahas in a clean ascending ladder, with Ketu excluded. The verified Santhanam allocation is Chandra 1, Surya 2, Guru (Jupiter) 3, Mangal (Mars) 4, Budha (Mercury) 5, Shani (Saturn) 6, Shukra (Venus) 7, and Rahu 8. The arithmetic is the triangular sum of one through eight: 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 = 36. Why Ketu carries no period here is not explained in the source verses, and commentators note the omission without resolving it.

A recurring confusion is worth naming plainly. Shattrimsha-sama is frequently mistaken for Yogini dasha, which is also a 36-year cycle whose eight lords also run from one to eight years and also excludes Ketu. The two are distinct systems with different lord-to-period mappings, different starting rules, and different classical lineages — Yogini carries a tantric pedigree, while Shattrimsha-sama sits squarely among Parashara's conditional udu dashas. An astrologer should not treat a Yogini calculation as a Shattrimsha-sama reading or the reverse.

The starting point is reckoned from the natal Moon's nakshatra. The count runs from Shravana to the nakshatra of the natal Moon, and that count divided by eight identifies the opening dasha lord, the remainder fixing where in the sequence the native begins; the balance of the first mahadasha is prorated from the Moon's travel through its nakshatra. Chandra's nakshatra group opens at Shravana, Surya's at Dhanishta, Guru's at Shatabhisha, and the ladder continues through the remaining lords to Rahu.

In reading practice the dasha behaves like the other Parashari period systems: each mahadasha subdivides into antardashas in the same lord-order and in proportion to each lord's share, and a period is judged by the ruling graha's dignity, ownership, and placement against the houses. Its place among the dashas is that of a conditional, charts-specific lens — a 36-year timing frame an astrologer takes up when the day or night hora condition is met, layered against the universal Vimshottari rather than displacing it. Among the sama dashas it is the shortest, the most compact expression of the equal-ascending principle.

How It Is Read

Shattrimsha-sama carries weight as the most compact of the equal-ascending (sama) dashas and as a clear case of a timing system selected by birth condition rather than applied universally. Its ladder of one through eight years gives each successive graha a measured increase of weight, so the cycle moves from the Moon's single year to Rahu's eight in an orderly progression — a structure distinct from the irregular shares of Vimshottari, where the longest period belongs to Venus. The day-from-Sun, night-from-Moon eligibility ties the dasha directly to the luminaries and to the moment of birth, making it a luminary-anchored reading for the charts that qualify. It also serves as a standing caution in dasha study: because it mirrors Yogini's 36-year, one-to-eight-year shape so closely, it teaches the practitioner to verify which system a calculation actually reflects before interpreting a period.

Connections

Shattrimsha-sama sits among the conditional and sama udu dashas: Chaturashiti-sama (84) and Dwisaptati-sama (72) are its equal-period kin, while Ashtottari (108), Shodashottari (116), Dwadashottari (112), Panchottari (105), and Shatabdika (100) round out the conditional set. Its closest solar relative is Shashtihayani (60), the other Sun-keyed conditional dasha, which also drops Ketu. It is most often confused with Yogini (36), sharing its span and one-to-eight ladder but not its mapping or lineage. The contrast with Vimshottari is structural: that system is universal and irregular, this one conditional and equal-ascending. It is unlike the rashi-based Jaimini Chara and the pada-based Kalachakra, neither a graha-period dasha. Its luminary trigger leans on Surya and Chandra through the hora of the lagna.

Further Reading

  • Brihat Parashara Hora Shastra, conditional-dasha chapters (R. Santhanam translation) — the source verses for Shattrimsha-sama's eligibility, period lengths, and Shravana-based reckoning.
  • Hart de Fouw and Robert Svoboda, Light on Life — chapter on the dasha systems and the logic of conditional selection.
  • K. N. Rao, The Nakshatra (Star) System of Prediction — treatment of the sama and conditional udu dashas.
  • B. V. Raman, Hindu Predictive Astrology — survey of the special dashas, including the Yogini comparison.
  • Sanjay Rath, dasha writings on the Parashari period systems and their applicability conditions.

Frequently Asked Questions

What is Shattrimsha-sama dasha?

Shattrimsha-sama Dasha (also Shat-trimsat-sama) is a conditional nakshatra-based timing system of 36 years described in the Brihat Parashara Hora Shastra. The term sama marks it as an equal-ascending dasha, its eight grahas holding one through eight years in sequence. It is preferred for births that meet a day or night hora condition tied to the Sun and Moon, and it serves as a specialist alternative to the universal Vimshottari dasha.

How long is the Shattrimsha-sama dasha cycle and how is it divided?

The full cycle is 36 years, distributed across eight grahas in an ascending ladder with Ketu excluded: Moon 1, Sun 2, Jupiter 3, Mars 4, Mercury 5, Saturn 6, Venus 7, and Rahu 8 years. These are the triangular sum of one through eight, which totals exactly 36. The Santhanam translation of the BPHS gives this order and these lengths; the omission of Ketu is noted but not explained in the source verses.

When is Shattrimsha-sama dasha used?

It is a conditional dasha, adopted when its eligibility mark is present: birth in daytime with the ascendant rising in the Sun's hora, or birth at night with the ascendant rising in the Moon's hora. The hora is the half-sign division, owned by the Sun and Moon in an order that alternates between odd and even signs. When the condition holds, an astrologer may apply this 36-year reading alongside the default Vimshottari.

How is the starting period of Shattrimsha-sama dasha calculated?

The opening lord is found from the natal Moon's nakshatra. The count runs from Shravana to the Moon's nakshatra, and that count divided by eight identifies the starting dasha lord, with the remainder fixing the position in the sequence. The balance of the first mahadasha is prorated from how far the Moon has travelled through its nakshatra, and the remaining lords follow in the fixed Moon-to-Rahu ladder.

How is Shattrimsha-sama dasha different from Yogini dasha?

Both run 36 years, assign their eight lords one through eight years, and exclude Ketu, which is why they are so often confused. They remain distinct systems: the lord-to-period mappings differ, the starting rules differ, and the lineages differ. Yogini carries a tantric pedigree, while Shattrimsha-sama is one of Parashara's conditional udu dashas. A calculation made for one should never be read as the other.