Shashtiamsa D60 Chart

What this section adds

The calculator above returns a D60 sign and a D60 house for your Ascendant and nine grahas, and the notes beside it describe the code in two short paragraphs. This section supplies what those notes leave out: the passage the rule comes from and the one place where that passage has to be interpreted, a table that lets you check any result by hand, the sixty names the classical text attaches to the amsas, the meaning of each field in the answer, what the old text says the chart is for, how the same ten signs are reused elsewhere in this app, and a measured account of how many minutes of clock error it takes to change the result. All figures come from the engine, run on the same sample birth the page already uses.

Where the Shashtiamsa rule is written

Brihat Parashara Hora Shastra names sixteen divisions of a sign in Ch. 6 Sl. 2-4. Shashtiamsa is the last name on that list, immediately after Akshavedamsa (D45). Its definition occupies Sl. 33-41, the longest passage given to any single division in the chapter. Most of that length is a list of sixty names. The computational part is three sentences.

In the translation held in our corpus, those sentences say: a Shashtiamsa is one sixtieth of a Rasi, or half a degree. To find its lord, ignore the Rasi position of the graha and take the degrees it has traversed in that Rasi. Multiply that figure by two and divide the degrees by twelve. Add one to the remainder, and that indicates the Rasi in which the Shashtiamsa falls. The lord of that Rasi rules the Shashtiamsa.

The passage then lists sixty names for an odd Rasi, from Ghora to CandraRekha, and adds that the order is reversed for an even Rasi 'in so much as these names are concerned'. It closes with a single sentence of interpretation: grahas in benefic Shashtiamsas produce auspicious results, and the opposite holds for grahas in malefic ones.

The use of the chart is given in the next chapter. Ch. 7 Sl. 1-8 assigns one subject to most divisions: wealth to Hora, spouse to Navamsa, power and position to Dashamsa, and so on. For the last two it does something different. It says that 'all indications' are to be read from both Akshavedamsa and Shashtiamsa. The same passage then cites an older authority by name: the Bhava whose lord is in a malefic Shashtiamsa will diminish, 'so say Garga and others'.

Turning the sloka into arithmetic

The rule has four steps, and three of them are unambiguous. Doubling the degrees converts them into a count of half-degree parts: a point at 13 degrees and some minutes has completed 26 or 27 amsas. Dividing by twelve and keeping the remainder throws away complete cycles of the zodiac, because twelve amsas map onto twelve signs and then the pattern starts again. Adding one turns a remainder that runs from 0 to 11 into a count that runs from 1 to 12, which is how the classical texts count: the first sign is counted as 1, never as 0.

The fourth step is where a reader has to decide something. The translated sentence says the result 'will indicate the Rasi' without stating where the count begins. The engine counts from the sign the point occupies, with that sign itself as 1. A remainder of 0 therefore returns the occupied sign, a remainder of 1 the next sign, and so on forward. The code comment states this reading in so many words: the cycle is 'counted onward from the Rasi the point occupies'. The instruction to ignore the Rasi position is taken as applying to the arithmetic only, so that 27 degrees of Cancer and 27 degrees of Leo give the same remainder but start their counts from different signs.

This is the opposite design from several neighbouring divisions. Shodashamsa (D16), Khavedamsa (D40) and Akshavedamsa all begin their counts from a small set of fixed signs chosen by the modality or the odd/even class of the birth-chart sign. Shashtiamsa in this engine has no such table. Its only input besides the degree is the occupied sign itself, which is why the code gives it a function of its own, separate from the shared routine the other equal-part vargas use.

The second decision concerns even signs, and here the engine's history is recorded in its own comment. An earlier version counted the twelve-amsa cycle backward for even signs. That was removed. The comment sets out the reasoning: the only reversal Sl. 33-41 states is attached to the sixty names. Elsewhere in the chapter, when an even sign is meant to change the resulting sign, the text says so by naming a different starting sign, as it does for Saptamsa (from the seventh sign, Sl. 10-11) and Dashamsa (from the ninth, Sl. 13-14). It never asks for a backward count. The engine now applies the arithmetic the sloka gives, forward, for all twelve signs. The comment keeps one worked case for the record: 7 degrees 20 minutes of Taurus is amsa 14, remainder 2, and Taurus plus two is Cancer, where the old backward count gave Pisces.

If another program gives you a different D60 sign for a point in an even sign, this is the most likely cause, and it is a difference in how the sloka is read, not a difference in astronomy. The second most likely cause is a degree that sits close to a half-degree boundary, covered in the section on birth-time sensitivity below.

The lookup table

Because only the remainder matters, the sixty amsas collapse into twelve steps, each reached five times within a sign. The table gives the five half-degree windows for each step. To check a result by hand, find the window that holds the point's degree within its birth-chart sign, read the step, and count that many signs forward from the birth-chart sign.

Two details of the code sit behind this table. The engine holds each degree to two decimal places before doubling it, so a boundary is decided on the rounded figure; the largest shift this can cause is half of a hundredth of a degree, or 18 seconds of arc. And the amsa number is capped at the sixtieth part, so a degree that rounds up to exactly 30.00 is kept in the last amsa of its own sign and is not pushed into a sixty-first that does not exist.

The sixty names, and why the calculator leaves them out

BPHS Ch. 6 Sl. 33-41 gives each amsa of an odd sign a name. The table arranges them so that each row holds the five amsas sharing one step from the lookup table above: the first row is the five amsas that return the occupied sign, the second the five that return the next sign, and so on. The spellings are those of the translation in our corpus.

Three things are worth noticing in that list. First, the names are not all different. Kaal appears three times (15, 32 and 44), Amrit three times (17, 38 and 57), and Ghora, Deva, Komal and Saumya twice each, so sixty amsas carry fifty-two distinct names. Second, the list is positional: it is tied to the amsa's number within the sign, not to the sign the amsa maps to. Two amsas in the same row of the table share a D60 sign and have unrelated names. Third, for an even sign the text says the order runs the other way, so the first half-degree of Taurus carries the sixtieth name and its last half-degree the first.

The passage says that grahas in benefic Shashtiamsas give auspicious results and grahas in malefic ones the opposite. In the translation we hold, it does not then say which of the sixty names belong to which group. A reader can see that some names are plainly gentle and others plainly harsh, but the text itself draws no line, and several names fall between. Classifying them would mean importing a list from somewhere outside our sources.

That is the reason the calculator returns signs and houses only. The engine's function does not compute a name, and its comment says the reversal for even signs therefore 'has nothing to act on here'. No field in the result carries a name, a deity, or a benefic or malefic label, and this page does not offer a reading of any name. The table above is reproduced as what the text contains, so that you can see what the classical D60 is and how much of it this tool deliberately does not attempt.

The sample chart, point by point

The page's worked example is a birth on 14 August 1994 at 06:42 in Ahmedabad. The table below shows what the engine did for each of the ten points: the sidereal degree within the birth-chart sign, the amsa that degree falls in (counted from 1), the step, and the D60 sign and house that result.

Take the Sun through the sloka's own wording. It has traversed 27.26 degrees of Cancer. Doubled, that is 54.52, of which the whole number is 54. Divide 54 by twelve: four complete cycles and a remainder of 6. Add one to get 7. The seventh sign counted from Cancer, with Cancer as the first, is Capricorn. The engine's zero-based version reaches the same place by adding 6 to Cancer.

Venus shows how close a point can sit to an edge. At 12.92 degrees of Virgo it is in the 26th amsa, one step forward, which gives Libra. Eight hundredths of a degree further, at 13.00, it would enter the 27th amsa and give Scorpio. That is under five minutes of arc, which Venus covers in less than two hours: it crosses at 08:32 that morning. For this one point in this one chart, the D60 sign should be held loosely between two neighbours, and that changes its house from the 11th to the 12th. Saturn is closer still. Retrograde, it stands at 16.50 degrees of Aquarius, on the line between the 33rd and 34th amsas as the engine rounds it; at 08:31 it slips back into the 33rd, and its D60 sign turns from Scorpio, an enemy sign, to Libra, its exaltation.

Jupiter and the Sun land in the same D60 sign, Capricorn, from quite different starting places: one from the 28th amsa of Libra and the other from the 55th of Cancer. The Moon and Saturn likewise meet in Scorpio. In a chart with only twelve possible outcomes and ten points, coincidences of this kind are ordinary. They are not conjunctions in the sky; the Moon and Saturn are four signs apart in the birth chart.

Reading every field of the result

The answer has the same shape as every other divisional calculator on this site, which makes results comparable across them.

• available: true when a chart was produced. When it is false the response carries a 'missing' value and a sentence explaining it, and no chart at all.
• input: an echo of what the engine actually used - the local date, whether a time and a place were present, whether an Ascendant could be computed, the resolved place label, the timezone and its offset, and whether that timezone had to be assumed.
• positions: one entry for the Ascendant and one for each of the nine grahas. Each has a D60 sign and a vargottama flag. Each graha also has a house number; the Ascendant has none because it defines the 1st house.
• vargottama: a list of the points whose D60 sign equals their birth-chart sign. It is empty in the sample.
• houses: twelve rows giving the sign on each D60 house, starting from the D60 sign of the Ascendant and running forward one sign per house.

The houses are whole-sign houses. There are no cusps and no degrees inside the D60 chart, because a varga assigns a point to a sign and nothing finer. A graha's house is simply the number of signs from the D60 Lagna to the graha's D60 sign, counting the Lagna's sign as 1. In the sample the D60 Lagna is Sagittarius, so Capricorn is the 2nd house and Scorpio, one sign behind, is the 12th. The birth-chart Lagna for the same person is Leo, which you can confirm with the Lagna calculator; the two charts share no house structure.

When no chart comes back

This calculator is registered as needing an Ascendant. If the birth time is missing, the response is available: false with missing set to 'birthTime'. If a time was given but the place did not resolve to real coordinates, missing is 'birthPlace'. In both cases nothing is estimated. This is stricter than the arithmetic requires, since a graha's D60 sign depends only on its own degree, but a D60 without a Lagna has no houses, and the engine's sample sweep below shows that the Moon's D60 sign changes many times in a day, so a date-only D60 would be wrong for the Moon more often than right. The article on what an unknown birth time costs lists which parts of a chart survive without a clock time.

What vargottama means at this resolution

A point is flagged vargottama when the step is zero, which happens in five half-degree windows per sign: just after 0, 6, 12, 18 and 24 degrees. Those windows add up to 2.5 degrees out of 30, so one position in twelve qualifies. The empty list in the sample is unremarkable. The flag here is a statement about two signs matching. BPHS does not single out a D60 vargottama for special treatment in the passages we hold, and the calculator attaches no meaning to it.

Rahu and Ketu

The two nodes are always exactly opposite, so they sit at the same degree of opposite signs: 25.40 degrees of Libra and of Aries in the sample. They therefore share an amsa number and a step. Because D60 counts from the occupied sign, equal steps from opposite signs end in opposite signs, and the nodes stay six signs apart in every D60 this engine produces. In divisions that count from a fixed start, such as Vimshamsa (D20) and Chaturvimshamsa (D24), the same geometry can put them in one sign. Neither outcome says anything about the person; it is a property of the counting rule.

What the classical text says the chart is for

Ch. 7 Sl. 1-8 gives D60 the widest brief of any division: 'all indications'. It then states one concrete rule of use, attributed to Garga and others, that a Bhava diminishes when its lord is in a malefic Shashtiamsa. Notice what that rule depends on. It is a statement about the amsa's quality, which comes from the list of names, not about the D60 sign or the D60 house. The classical use of this division, as far as our source describes it, runs through the names. A tool that returns signs and houses is supplying the placements the text defines and stopping before the part the text leaves under-specified.

The second thing the text does with D60 is weight it. Ch. 7 describes four schemes for a 20-point strength called Vimshopak Bal, each built on a different set of divisions.

The pattern is clear. In the two smaller schemes D60 does not appear at all. The moment it is admitted, in the ten-division scheme, it takes a quarter of the whole score and outweighs the birth chart itself. In the sixteen-division scheme it remains the single largest share. A division that is absent from the everyday sets and dominant in the complete ones is being treated as a fine instrument: decisive when the data supports it, left out when it does not.

The same reticence shows in Shad Bala. BPHS Ch. 27 builds one component of positional strength, Sapt Vargaj Bal, from seven divisions: Rasi, Hora, Drekkana, Saptamsa, Navamsa, Dwadasamsa and Trimshamsa. Shashtiamsa is not one of them. So the Shad Bala calculator on this site makes no use of the D60 sign, while the Vimshopaka score does.

How this app uses the D60 sign elsewhere

The Vimshopaka Bala calculator uses the sixteen-division scheme with the weights from Sl. 21-25, so D60 contributes up to 4 of each graha's 20 points. The weights are the cited part. How much of each weight a graha earns is this codebase's own stated choice: it takes the graha's dignity in the varga sign on the same 0 to 10 scale the Shad Bala code uses, and awards that fraction of the weight. Exalted earns the full weight, own sign three quarters, a friendly sign five eighths, a neutral sign half, and an enemy sign or debilitation nothing. BPHS Sl. 21-25 describes its own reductions (20 falling to 18, 15, 10, 7 and 5 across named grades); the engine's comment says plainly that it is not reproducing that table verbatim.

For the sample birth the D60 line of that calculation comes out as follows.

This is an unusual chart for D60: three grahas fall in their debilitation signs and three in enemy signs, so six of the seven earn nothing from the most heavily weighted division. Venus alone collects 3 of its 4 points. The effect on the totals is visible. No graha reaches the 15 that Sl. 26-27 names as the threshold for wholly favourable effects, and the engine's bands, which follow the text's cut-offs at 5, 10 and 15, place five of the seven in 'moderate'.

It also shows the fragility that comes with the weight. Venus was noted above as sitting one hundredth of a degree from the next amsa. Across that edge its D60 sign would be Scorpio and no longer its own Libra, and its 3 points from D60 would be re-graded on Scorpio's dignity. A 4-point weight resting on a half-degree window means a small uncertainty in position can move a 20-point score by more than any other single division can. The Vimshopaka score needs no birth time, since it reads signs and not houses, but it does inherit this sensitivity to the degree.

Inside the signed-in product the same function feeds the Kundali view, where Shashtiamsa appears as one of the divisional wheels. The payload carries it only when the chart has an Ascendant and sets it to null otherwise, the same rule the public calculator applies.

Birth-time sensitivity, measured

An amsa is half a degree. The Ascendant travels the whole zodiac in a little under a day, so it crosses 720 of them in that time. To see what this means in clock minutes, the engine was run once for every minute of the sample's civil day in Ahmedabad, 1,440 charts in all, and the D60 sign of each point was recorded.

The Ascendant line is the one that governs the houses. Around the sample's recorded time, the engine gives the D60 Lagna as Libra at 06:37 and 06:38, Scorpio at 06:39 and 06:40, Sagittarius at 06:41 and 06:42, Capricorn at 06:43 and 06:44, and Aquarius from 06:45 to 06:47. The recorded 06:42 is the last minute of its window. A birth that actually took place one minute later would move the D60 Lagna to Capricorn and renumber every house in the chart: Rahu would leave the 1st house for the 12th, and the Moon and Saturn would move from the 12th to the 11th.

Compare that with the Navamsa, whose part is 3 degrees 20 minutes and whose Lagna holds for roughly a quarter of an hour at a time. The article on the Navamsa and birth time works through that case. D60 is between six and seven times finer. A hospital record rounded to five minutes spans two or three D60 Lagnas, and a time remembered to the quarter hour spans seven or eight.

The practical reading of the result follows from that. The D60 signs of the slow grahas are stable against any plausible clock error: Jupiter and the nodes did not change all day, and Saturn changed only because it sits on an edge. The Sun, Mars, Venus and Mercury are stable against an error of an hour or more unless they happen to sit near an edge. The Moon's D60 sign is good only if the time is right to within some tens of minutes. The D60 Lagna and every house number need the time to the minute, and they also need the place's coordinates and timezone to be right, since each of those shifts the Ascendant in the same way a clock error does.

There is a second, independent limit. The methodology page describes the positions as computed from published formulas, not from an ephemeris file, and the calculator's own notes put the accuracy at a few arcminutes for planets and about a tenth of a degree for the Moon. A tenth of a degree is a fifth of an amsa. So even with a perfect birth time, a Moon within a tenth of a degree of a half-degree boundary could fall either side, and another program using a different model or a slightly different ayanamsa value may legitimately disagree with this one there.

What this calculator does not do

• It does not name the amsa, give its deity, or classify it as benefic or malefic. The names are in the text; a dependable classification of them is not in the sources we hold.
• It does not interpret the D60 houses. BPHS gives no house-by-house reading for this division in the chapters we have, and the page does not supply one.
• It makes no statement about earlier lives or about the future. The classical brief is 'all indications', which the engine reports as placements and nothing more.
• It does not estimate a chart from a date alone, and it does not correct or rectify a birth time.
• It does not compute the Varg designations of Ch. 6 Sl. 42-53, such as Parijata or Sri Vallabh.
• It does not count even signs backward. If you are comparing against a tool that does, the results for points in even signs will differ by design.

Where to go from here

The natural starting point is the birth chart, since every D60 sign is derived from a degree in it; the birth chart calculator shows those degrees. From there the Navamsa (D9) is the division BPHS weights next after D60 in the full scheme and the one most readers can use with an ordinary birth record. The Akshavedamsa (D45) is the division the text pairs with D60 under 'all indications', and with a 40-arcminute part it is almost as demanding of the clock. The Vimshopaka Bala score is where the D60 sign actually changes a number you can compare across grahas.

For the texts themselves, the sources page lists the books this site draws on and how each was read, and the full set of divisional and other tools is on the calculators index.

Questions people ask about D60

Is D60 really more important than the birth chart?

In two of the four Vimshopak schemes in BPHS Ch. 7 it carries more points than the Rasi chart: 5 against 3 in the ten-division scheme and 4 against 3.5 in the sixteen-division scheme. In the two smaller schemes it is not used at all. The text weights it heavily where it is admitted; it does not say that it replaces the birth chart, and every D60 placement is itself derived from a birth-chart degree.

My D60 Lagna changed when I altered the time by two minutes. Is that a bug?

No. The Ascendant crosses a half-degree amsa about every two minutes, and each crossing moves the D60 Lagna one sign forward. In the sample day the engine recorded 722 changes. If your birth time is known only to the nearest five or ten minutes, treat the D60 houses as several candidate charts and the planets' D60 signs as the dependable part.

Another site gives a different D60 sign for one of my planets. Which is right?

Check two things. If the planet is in an even sign (Taurus, Cancer, Virgo, Scorpio, Capricorn or Pisces), the other tool may be counting backward for even signs; this engine counts forward for all signs and explains why in its code comments. If the planet is within a few arcminutes of a half-degree mark, the two tools' positions may simply fall on opposite sides of the edge. Neither case can be settled by this page alone.

Why doesn't the result show the amsa's name, like Ghora or Amrit?

The engine does not compute it. BPHS lists the sixty names and says benefic ones give good results and malefic ones the opposite, but the translation we hold does not say which names are which. Showing a name without a sourced classification would invite a reading the sources do not support, so only signs and houses are returned. The full list is in the table above.

Can I use D60 without a birth time?

Not through this calculator; it returns no chart without an Ascendant. The D60 signs of slow grahas would usually be the same at any hour of the day (the sample's Saturn, sitting on an edge, is an exception), but the Moon's changes roughly every 51 minutes and there would be no houses. The Vimshopaka Bala calculator does use D60 signs from a date alone, with the caveat that its Moon line is then only as good as the assumed time.

Does a planet being debilitated in D60 mean something bad?

The only thing this app does with that fact is arithmetic: in the Vimshopaka score, a debilitated D60 sign earns none of the 4 points D60 can contribute. BPHS frames D60 quality through the amsa names, not through the dignity of the D60 sign, and gives no verdict on a person from either. A low line in a strength table is a measurement on a stated scale, not a forecast.

Why are Rahu and Ketu always in opposite D60 signs here?

They are at the same degree of opposite signs, so they take the same step, and this division counts that step from the sign each occupies. Equal steps from opposite signs end six signs apart. In the sample both are in the 51st amsa with a step of two, giving Sagittarius from Libra and Gemini from Aries.

Are the D60 houses computed with cusps, like some house systems?

No. The D60 sign of the Ascendant is the whole 1st house, the next sign is the 2nd, and so on. A divisional chart places a point in a sign and carries no degree inside that sign, so there is nothing from which a cusp could be drawn.