Ardha Ashtama Sani: Saturn in the 4th from your Moon, what the rule is and when it runs

Ardha Ashtama Sani is the least discussed of the three Saturn periods this app names, and the one with the thinnest source. This page sets out what the engine computes, the real dates for each Moon sign and exactly what the literature says. The Ashtama Sani calculator answers for today from a birth date; the long-form beneath it covers the arithmetic, the lookup table and birth-time sensitivity, and they are not repeated here.

What Ardha Ashtama Sani is, and how this app computes it

Ardha means "half". Ashtama Sani is Saturn in the 8th sign from the Moon, and Ardha Ashtama Sani - "half of Ashtama Sani" - is Saturn in the 4th, four being half of eight. Both are counted from your Moon sign at birth, the Moon sign itself being the 1st, as every rule of Gochara is. The ascendant plays no part.

The engine function is the same one that computes Ashtama Sani, computeAshtamaSani() in kundaliEngine.js. It counts inclusively from the natal Moon's sign to transiting Saturn's sign. A count of 4 returns active: true with the name "Ardha Ashtama Sani"; a count of 8 returns Ashtama Sani; every other count returns active: false. It is a comparison of two whole signs: Saturn at the first degree of the 4th sign and at the last count the same, and Saturn's strength, speed and direction are not consulted.

The sentence shown with an active result reads: "Saturn is transiting the 4th sign from your natal Moon - a period classically read as testing domestic peace and family matters, calling for patience at home rather than signalling anything fixed or fated." It is identical for every person in the period.

Because the 4th from one Moon sign is the 8th from another, every Ardha Ashtama Sani window is also somebody else's Ashtama Sani. Saturn in Pisces today is the 4th from Sagittarius and the 8th from Leo, so those two Moon signs share the same dates under different names.

What the sources say, and how little

A search of the Brihat Parashara Hora Shastra translation in this app's source library for "ardha", "ashtam" and "asthama" finds no passage naming this period. Saravali and the Bhrigu Sutras do not name it either.

The single source in the library is Advanced Predictive Astrology (Vol. II), in its chapter "Research on Transits", p. 313. In one paragraph it says that Saturn in the 4th house of the Moon "generates this evil yoga", reasons that the 4th rules happiness of mind, and so reads the period as one of family unhappiness. It lists loss of relations, loss of money, loss of happiness and separation from relatives as its outcomes, and illustrates it with one person's bereavement, which this page does not repeat. That is the whole of the classical-sounding case: a definition, a reason drawn from house meaning, a list and one anecdote.

The engine keeps the definition and the theme and drops the rest. "Evil yoga" becomes "a period classically read as testing domestic peace and family matters", and the list of losses becomes "calling for patience at home rather than signalling anything fixed or fated".

The older texts, indirectly

BPHS supplies the ingredients but not the period. Its house lists make the 4th the house of mother, happiness, lands and conveyances (the 4th house page goes through them). Its Ashtakavarga gives a second, independent hint: in Saturn's own table (Ch. 66 Sl. 59-60), only the Lagna and the Sun give Saturn a point in the 4th from themselves. The Moon does not. In BPHS terms, the Moon never supports Saturn in the 4th from her, while she does support Saturn in the 3rd, 6th and 11th.

Saravali Ch. 53 Sl. 9-10 adds a qualifier that matters more for this period than for most: a transit's adverse results are heavier when the graha crosses its debilitation or an enemy's sign and lighter in its own, exaltation or a friend's sign. BPHS Ch. 3 Sl. 49-50 puts Saturn's exaltation in Libra and its debilitation in Aries. So for a Capricorn Moon, whose 4th is Aries, every Ardha Ashtama Sani is Saturn in its sign of fall; for a Cancer Moon, whose 4th is Libra, every one is Saturn exalted. The engine applies neither qualifier; the Saravali rule is reported here as the text's claim.

How the Gochar reading of the 4th was corrected

The Gochar calculator grades all nine grahas from your Moon by the transit rules of S. Kannan's Fundamentals of Hindu Astrology (Ch. XXXI, pp. 117-118), as quoted in the engine. Kannan states the bad positions twice. One stronger sentence, with escalating wording that is harshest for Saturn, names the 1st, 8th and 12th. A second, plainer sentence says that malefics "give bad results when they occupy the 1st, 4th, 8th or 12th house".

The engine once tested only the first sentence. Every graha in the 4th from the Moon, Saturn included, fell through to "classically unremarkable" - the opposite of the text. A comment headed "THE 4TH FROM THE MOON - CORRECTED" records the fix. The 4th now returns "testing", with a note of its own: "classically unfavourable from your Moon - the source lists the 4th among the bad transit positions for benefics and malefics alike, so steadiness serves better than new commitments here". For Saturn the note adds "(for Saturn this is also Ardha Ashtama Sani)". The 4th is deliberately kept out of the "most intense" wording reserved for the 1st, 8th and 12th, because only the plainer sentence mentions it.

The result is that the two screens now agree. During Ardha Ashtama Sani, the Ashtama Sani calculator names the period and the Gochar calculator grades Saturn "testing" with a note that names it too.

Every Moon sign's Ardha Ashtama Sani window

The table gives each Moon sign's current or next complete window from the engine's Saturn ingresses, or the most recent one where the next runs past the 2050 end of the ingress table. The window runs from Saturn's first entry into the 4th sign to its final exit; "days inside" counts only the days it is actually there.

On 13 October 2026, with Saturn in Pisces in this engine (29 March 2025 to 2 June 2027), the Moon sign in Ardha Ashtama Sani is Sagittarius. The next to enter is Capricorn, when Saturn first crosses into Aries on 2 June 2027; the Saturn transit in Aries page follows that passage sign by sign. All dates are this app's, and near an ingress other software can differ by hours to a day or two.

If you want to look back rather than forward, the previous round of windows in the same table ran as follows, each from first entry to final exit: Scorpio Moon 1993 to 1996, Sagittarius 1995 to 1998, Capricorn 1998 to 2000, Aquarius 2000 to 2003, Pisces 2002 to 2005, Aries 2004 to 2007, Taurus 2006 to 2009, Gemini 2009 to 2012, Cancer 2011 to 2014, Leo 2014 to 2017 and Virgo 2017 to 2020. Neighbouring windows overlap by months, because a retrograde can carry Saturn back into the previous sign after it has opened the next Moon sign's window.

Across the 21,540 days from 15 December 1990 to 5 December 2049, each Moon sign spends between 7.4 per cent (Pisces, 1,592 days) and 9.2 per cent (Libra, 1,980 days) of the time in Ardha Ashtama Sani. A complete window in the ingress table lasts between 773 and 1,093 days from first entry to final exit, and the days actually inside run from 773 to 1,020. Three complete windows are single unbroken stays; four are split twice by retrogrades; the rest are split once.

Saturn's 10th aspect falls on your Moon sign

One feature of the 4th sets it apart from the other named periods. The engine's aspect function gives Saturn its universal 7th aspect and its special 3rd and 10th (the drishti BPHS assigns it). Counted from the 4th sign from your Moon, the 10th aspect lands on the 1st - your Moon sign itself. The 3rd aspect lands on the 6th from the Moon and the 7th aspect on the 10th.

Advanced Predictive Astrology, on the same p. 313, says that transiting Saturn casting its 3rd, 7th or 10th aspect on the natal Lagna, Sun or Moon brings distress. Ardha Ashtama Sani therefore always satisfies the Moon half of that condition. In Sade Sati, by contrast, Saturn is on the Moon sign only in the middle phase and aspects it from neither neighbour; in Ashtama Sani none of its aspects reaches the Moon sign.

The same arithmetic produces a tension inside the book. Saturn aspects the Moon sign from three positions: the 4th, the 7th and the 11th. The 11th is one of the places the same chapter (p. 311) says Saturn "gives good results", and the engine calls it favourable for every graha. The book does not reconcile its aspect remark with its 11th-house remark, and this page does not try to. The engine computes no transit aspects at all, so none of this appears on any screen.

Worked example: a Capricorn Moon, 1998-2000 and 2027-2030

Take a natal Moon in Capricorn. The 4th sign from it is Aries. The engine was run for this Moon sign at 12:00 IST on a sample day in each of Saturn's stays around the next window.

The window spans 1,049 days (2.87 years) from 2 June 2027 to 16 April 2030, of which Saturn is in Aries for 864: 141, then 531, then 192. Twice it pauses, for 124 days and for 61 days. The first pause shows the Gochar correction at work. Through late 2027 a Capricorn-Moon reader would see the Gochar grade for Saturn swing from "favourable" (3rd) to "testing" (4th), back to "favourable" and back to "testing" as Saturn crosses and recrosses the Pisces-Aries boundary.

The previous Capricorn-Moon window had none of this. Saturn entered Aries on 18 April 1998 and left on 7 June 2000 without turning back across either boundary: 781 days, one entry. The engine run for 1 January 1999 puts Saturn at 2.78 Aries and returns Ardha Ashtama Sani. Both windows are Saturn in Aries, its debilitation sign by BPHS Ch. 3 Sl. 49-50, so on Saravali's qualifier both would read heavier than the same period for most other Moon signs; the engine shows them identically to every other Ardha Ashtama Sani.

Where it falls in the Capricorn Moon's Saturn calendar

Ardha Ashtama Sani usually arrives soon after Sade Sati ends, with one sign between them. For a Capricorn Moon, the engine's Sade Sati ran from 26 January 2017 to 29 March 2025. Saturn then spends 795 days in Pisces, the 3rd from this Moon - the position Advanced Predictive Astrology describes as "turning a new leaf" after Sade Sati, and which both its list and the engine call good. Then comes Ardha Ashtama Sani in Aries from 2 June 2027. After it ends on 16 April 2030, 2,326 days pass before Ashtama Sani begins on 28 August 2036. For this Moon sign the run of the 2020s is therefore: Sade Sati, a favourable interval, Ardha Ashtama Sani, and then a long interval with none of the three. Over the 21,540 days from 15 December 1990 to 5 December 2049, a Capricorn Moon spends 26.8 per cent of the time in Sade Sati, 7.6 per cent in Ardha Ashtama Sani, 8.1 per cent in Ashtama Sani and 57.5 per cent in none of them.

The worked example shows only what the rule computes. It does not describe what any Capricorn-Moon person experienced in 1998-2000 or will experience in 2027-2030.

Cancellations and exceptions

The engine applies none, and the one source that names the period states none. The exceptions Advanced Predictive Astrology does give - a yogakaraka, well-supported Saturn, or a Moon placed with Saturn at birth - are written about Sade Sati (pp. 311-312), not about the 4th, so this app does not carry them across. The BPHS Ashtakavarga rule and Saravali's dignity rule grade a transit's strength; they do not cancel it.

If you want to see which way that grading leans for your chart, the Ashtakavarga calculator shows Saturn's points in every sign, and the birth chart calculator shows your ascendant and the sign on each house, from which you can read whether Saturn rules a kendra or a trikona for you.

What Ardha Ashtama Sani does not tell you

As with every named rule on this site, including Mangal Dosha and Kaal Sarp Dosha, the result describes a position. It is not a verdict on a home or a family.

• It does not predict events. The engine returns one sentence for everyone in the period and nothing about your circumstances.
• It does not weigh Saturn's dignity, its Ashtakavarga points, its aspects or its role in your chart.
• It does not read your running dasha. The source chapter itself treats dasha and transit as two limbs, each incomplete without the other.
• It is shared by everyone with your Moon sign. At any moment exactly one of the twelve Moon signs is in it.
• It does not count from the ascendant. Saturn natally in the 4th house is a separate, permanent placement.
• It is not a reason to buy anything, and no remedy is offered.

For the natal side, see Saturn in Vedic astrology and Saturn in the 4th house. Your running periods are on the Vimshottari Dasha calculator, and the term is defined briefly under Ashtama Sani in the glossary. How positions are computed is on the methodology page.

Is Ardha Ashtama Sani in BPHS?

No passage in the BPHS translation this app uses names it, and Saravali and the Bhrigu Sutras do not either. The definition in this library comes from one paragraph of Advanced Predictive Astrology, p. 313.

Which Moon sign is in Ardha Ashtama Sani now?

On 13 October 2026, with Saturn in Pisces in this engine, it is Sagittarius. Sagittarius's window runs from 29 March 2025 to 22 February 2028, with a 141-day break in 2027 while Saturn is in Aries.

How long does it last?

In this engine a complete window spans between 773 and 1,093 days from first entry to final exit, with Saturn actually in the 4th sign for 773 to 1,020 of those days. Most windows are interrupted once by a retrograde.

Is Ardha Ashtama Sani milder than Ashtama Sani?

The source does not rank them. The engine's Gochar screen gives Saturn's 8th the "most intense" wording and the 4th a plainer "testing" note, because that is how its source words them, and the app's risk scorer weights the 8th above the 4th. That is a difference in the texts' emphasis, not a measured difference in outcomes.

Why did the Gochar calculator once call Saturn in my 4th "unremarkable"?

Because of a bug, since fixed. The engine used to test only the 1st, 8th and 12th, so the 4th fell through to the neutral default. The source lists the 4th among the bad positions, and the engine now returns "testing" and names Ardha Ashtama Sani in the note.

Does the result depend on Saturn being debilitated or exalted?

Not in this app. Saravali says a transit's effect is heavier in debilitation and lighter in exaltation, and Saturn is debilitated in Aries and exalted in Libra, but the engine returns the same answer whatever sign the 4th happens to be.

Does this period mean trouble at home?

It means Saturn is in the 4th sign from your Moon. The one source that names it reads that as family strain; the engine states the theme as a call for patience at home and explicitly not as anything fixed or fated. It makes no prediction about any household.

Does the app recommend remedies for Ardha Ashtama Sani?

No. This app prescribes no mantras, gemstones, pujas or donations for this or any other period.