When a graha comes too close to the Sun it is said to be asta - set, or combust. While Jupiter or Venus is asta, most Indian almanacs stop printing wedding muhurtas, which is why the marriage season pauses for weeks at a time. This calendar shows every asta window of the year for Jupiter, Venus, Mercury, Mars and Saturn - computed twice, under each of the two orb tables in circulation, with the gap between them stated in days.
How close to the Sun a graha must come before it counts as asta is not settled. This page computes every window twice - once with the wider orbs this app applies elsewhere, and once with the narrower set recorded in its research bank - and shows you both. Neither is averaged into the other, and neither is marked as the right one.
On Venus the two differ by three degrees, and because Venus separates from the Sun very slowly around a superior conjunction, three degrees can be more than three weeks of calendar. That is why the gap is printed as days beside every window rather than left for you to work out.
Degrees of longitude either side of the Sun. A graha inside this arc counts as asta.
| Graha | Wider tableSūrya Siddhānta degrees, read as a longitude orb | Narrower tablePrasna Tantra, General Introduction (tr. B. V. Raman, 1969) |
|---|---|---|
| Jupiter (Guru) | 11° | 9° |
| Venus (Shukra) | 10° · 8° retro | 7° |
| Mercury (Budha) | 14° · 12° retro | 8° |
| Mars (Mangal) | 17° | 12° |
| Saturn (Shani) | 15° | 9° |
| Moon (Chandra) | 12° | not stated |
Wider table: Wider orbs, so every window opens earlier and closes later. This is the set the rest of the app already applies - the combustion flag on your kundli, and the asta warning on the muhurat finders, both come from these degrees.
Narrower table: Narrower orbs, so every window is shorter at both ends. It answers for five grahas only: no Moon figure, and no separate retrograde allowance - the one degree figure is applied whichever way the graha is moving.
Each day of the year is sampled, the angular distance between the graha and the Sun in longitude is measured to sub-arcsecond precision, and every crossing of an orb limit is then narrowed down to within about twenty minutes. Dates are given in UTC and to the day; a window that begins late in the night may read as the following date in your own timezone.
This is a longitudinal orb, which is what every table above states. It is not a calculation of true heliacal setting and rising - when the graha actually disappears into and reappears from the twilight, which depends on its latitude, its brightness and your horizon. Those dates differ, sometimes by several days, and this page does not claim them.
Planning a wedding date? The vivah muhurat finder scores days one at a time and marks the ones on which Jupiter or Venus is asta by the wider table above.
Asta means 'set'. A graha within a certain arc of the Sun rises and sets so close to it that it is lost in the glare and cannot be seen at all - Venus vanishes from the evening sky, reappears weeks later before dawn, and in between it is asta. The astrological convention keeps that name and measures the condition as an arc: if the difference in longitude between the graha and the Sun is smaller than a stated number of degrees, the graha is combust.
That is a purely geometric test, and it is what this page computes. Two things follow from it. First, no birth details are needed: combustion is a fact about the sky on a date, the same for everyone on Earth. Second, the answer depends entirely on the number of degrees you use - and that number is exactly what is not settled.
The table this app applies elsewhere - on your kundli's combustion flag and on the muhurat finders - gives Mars 17 degrees, Mercury 14 (12 when retrograde), Jupiter 11, Venus 10 (8 when retrograde), Saturn 15 and the Moon 12. It is the set most modern software uses, and its numbers are the Surya Siddhanta's own degrees of setting, one for one - chapter IX verses 6 to 8 for the five planets, with the smaller Venus and Mercury figures for their retrograde side, and chapter X verse 1 for the Moon.
The other set is recorded in this project's research bank from the General Introduction to B. V. Raman's 1969 translation of Prasna Tantra, alongside the Tajika orbs of light: Mars 12, Mercury 8, Jupiter 9, Venus 7, Saturn 9. It is narrower on every graha. It also states nothing at all for the Moon, and gives no separate figure for a retrograde graha.
On Venus that is 7 degrees against 10, and the difference is not academic. Around a superior conjunction Venus pulls away from the Sun at roughly a quarter of a degree a day, so three degrees of orb is over three weeks of calendar. A family that has been told 'no weddings while Shukra is asta' is looking at two answers a month apart. This page prints both windows and the number of days between them, and it does not average them or name a winner - where two traditions genuinely differ, this app renders the disagreement.
What the Siddhanta does not do is use those numbers the way modern practice does. It gives them as kalamsas - degrees of time in oblique ascension, the distance at which a graha becomes visible on the horizon - and practice reads them as a distance from the Sun along the ecliptic. So the wider set is labelled a modern synthesis: a classical number put to a modern use. Reckoning the kalamsa as the text means it would need a true heliacal visibility calculation, which this page does not claim to do.
Jupiter and Venus are the two grahas the wedding-season rule names, and the observance is straightforward: while either is asta, the vivaha muhurta list in an almanac goes empty. This app carries the same bar on six further rites - griha pravesh, griha-arambha, upanayana, karnavedha, aksharabhyasa and seemantonnayana - and deliberately does NOT carry it on mundan or namkaran, because the chapters those two rows are built from do not state it. Because Jupiter is asta for about a month in most years and Venus for anywhere between ten days and three months depending on which side of its orbit it passes, these windows take out a large part of some years.
This is a statement about what almanacs do, not a reading of what an asta Jupiter means for a marriage. This app has not traced the observance to a specific chapter and verse in a muhurta text, and says so rather than borrowing authority from a neighbouring citation. What it can do exactly is the arithmetic: here are the windows, on both readings, to the day.
Each graha gets its own card, with Jupiter and Venus first. Every window is shown twice - once from the wider table and once from the narrower - with a bar that draws the narrower window nested inside the wider one, so you can see at a glance how much of the difference sits at the start and how much at the end.
Dates are UTC and given to the day. The underlying scan finds each crossing to within about twenty minutes, so a window that opens near midnight may read as the next date in your own timezone; when a date is that close to the line, treat the day itself as the boundary rather than the answer.
A Venus window of ten days and a Venus window of three months are two different conjunctions, not an error. What sets the length is the SPEED at which Venus crosses the orb, not the size of the orb: at an inferior conjunction it is retrograde and closes on the Sun at about one and a half degrees a day, while at a superior conjunction it creeps away at roughly a quarter of a degree a day - six times slower across nearly the same arc. You can check that on this page: the narrower table applies one figure of seven degrees to Venus whichever way it is moving, and its two windows still come out about nine days and about eight weeks.
For educational purposes. Astrological interpretations are traditional and not a substitute for professional advice.