In Jyotisha, Sade Sati names Saturn’s transit through three sidereal rāśis centered on the natal Moon’s rāśi. Prokerala’s calculator explanation describes the span as beginning when Saturn enters the sign immediately before the birth Moon’s sign and ending when Saturn leaves the one immediately after it. Saturn spends roughly two and a half years in each sign, which gives the familiar approximate seven-and-a-half-year name. It is an average shorthand, not a fixed date interval.
The three sign positions
| Phase label | Saturn’s sidereal sign | Counted from natal Moon |
|---|---|---|
| Rising | The sign before the Moon sign | 12th |
| Peak | The Moon sign itself | 1st |
| Setting | The sign after the Moon sign | 2nd |
Drik Panchang’s explanation identifies the 12th, natal, and second sign passages as three phases. The names “rising,” “peak,” and “setting” are a convenient public-calculator vocabulary, not measured intensities. This tool assigns a phase solely by sign. It does not calculate aspects, the natal condition of Saturn, a dasha, or other factors that a practitioner might include.
Worked sign example
For an Aries natal Moon, Pisces is the sign before Aries. Saturn in sidereal Pisces is the rising phase; Saturn in sidereal Aries is the peak phase; Saturn in sidereal Taurus is the setting phase. The order wraps around the zodiac: for a Pisces natal Moon, Aquarius, Pisces, and Aries fill the three positions. No birthplace is needed to classify a transit after the natal Moon sign has been established.
Why the table has extra rows
Saturn can appear to move backward against the stars because Earth and Saturn orbit at different speeds. A direct ingress, retrograde return, and second direct ingress can create repeated entries in the same phase or a temporary break at the edge of the three-sign zone. The calculator samples Saturn’s apparent geocentric ecliptic longitude every twelve hours and refines a detected sign crossing to approximately one minute. It preserves these re-entries as separate intervals. A pair of crossings inside a single twelve-hour sample could be missed, though Saturn’s slow motion makes that an unusual edge case.
What the dates measure
The numerical pipeline uses Astronomy Engine 2.1.19 for apparent geocentric Saturn longitude in the true ecliptic and equinox of date. It subtracts this site’s approximate Lahiri ayanamsa, derived from a J2000 reference value, precession polynomial, and nutation term. A sidereal longitude enters the next equal 30° sign when it crosses a multiple of 30°. The calculation covers a 35-year UTC window beginning at midnight on January 1 of the selected start year. It accepts start years 1900–2050, so the last possible window ends in 2085.
Our approximation is stated as such; it is not a Swiss Ephemeris run. Near an ingress, another published calendar may put the sign change at a different minute or even on a different local date. Convert UTC to your own zone only after choosing the convention you want to compare.
What this rule does not decide
A transit interval does not predict whether something good or bad will happen. Prokerala notes differences of opinion about the interpretation of Sade Sati. Drik Panchang also describes both favorable and unfavorable possibilities under its tradition. This page keeps the computable sign membership separate from those claims. It neither scores a person’s circumstances nor gives health, relationship, or financial advice.
Frequently asked questions
Do I use my Sun sign?
No. The reference sign is the Moon’s rāśi at birth in the same sidereal convention. A Janma Rashi lookup can help identify it if the birth record is known.
Why does the first interval say “range begins”?
Saturn was already in that sign at midnight UTC on January 1 of the chosen start year. The tool does not infer a start date outside the selected 35-year window. Choose an earlier start year to include the actual ingress.
Can the total be shorter or longer than seven and a half years?
Yes. The phrase is approximate, and repeated sign crossings change the sequence of continuous intervals. The tool shows the actual modeled boundaries rather than forcing a single fixed duration.