Vyatipata

Vyatipata is the seventeenth nityayoga, and its name denotes a great calamity or a grievous falling-together. It is one of the most strongly inauspicious yogas, and in some reckonings the days it governs are set aside for expiation and charity rather than ordinary activity. The panchanga counts it among the configurations most to be avoided for auspicious undertakings. Reckoned like the others from the summed longitude of Sun and Moon divided into twenty-seven parts, it takes its place through the lunar month. These are the conventions of the calendar tradition, which fixes the malefic character of Vyatipata; an astrologer selecting a muhurta avoids it. The astronomical basis is only the combined motion of the two lights, which produces the arithmetic the tradition reads.

Vyatipata is one of only two yogas, with Vaidhriti, the twenty-seventh, that classical sources single out for a specific ritual response rather than simply advising avoidance: some Dharmashastra and later panchanga literature prescribe that a person who happens to die during Vyatipata, or whose birth falls under it in a strongly afflicted configuration, undergo a particular expiatory rite, shanti karma, to counteract the inauspicious timing, a practice distinct from and more elaborate than the ordinary advice simply to avoid beginning new undertakings that applies to the other seven inauspicious yogas. Vyatipata and Vaidhriti between them are generally regarded as the two most severely inauspicious of the full set of twenty-seven.

Of the five limbs of the panchanga the yoga is the most purely arithmetical, and the only one a person standing outside at night could never read off the sky. Where the tithi measures the Moon's separation FROM the Sun, the yoga measures the two longitudes ADDED together, and cuts the resulting circle into twenty seven equal arcs of thirteen degrees twenty minutes. Vyatipata is the arc from 213 degrees 20 minutes to 226 degrees 40 minutes of that sum. The sum climbs at roughly fourteen degrees ten minutes a day, so a yoga runs about twenty two and a half hours on average, a little shorter than a tithi, and like a tithi it can be skipped between two sunrises or carried across two of them.

The twenty seven arcs are the same width as the twenty seven nakshatras, and Vyatipata is the seventeenth arc of the grid in both schemes, which is why the two are often tabulated side by side. They are not the same thing and share nothing but their arithmetic: a nakshatra is a segment of the sky the Moon is physically standing in, while a yoga is a number derived from two positions and belongs to no part of the sky at all. Reading a yoga as a star group is the commonest confusion the term invites, and the shared name of the seventeenth position, Anuradha, is where it usually starts.

Vyatipata is one of the two yogas the almanac singles out beyond the ordinary auspicious and inauspicious grouping. Vyatipata and Vaidhriti are together called the maha pata yogas, and they are marked in almanacs that mark nothing else about the yoga at all: many printed panchangas carry the yoga column purely so that these two can be found. Both fall where the sum of the longitudes reaches a value the tradition treats as a break rather than a transition, and both are held to make the whole day unsuitable for anything undertaken for the first time.