Sadhya

Sadhya is the twenty-second nityayoga, and its name means that which can be accomplished, the attainable. It is one of the auspicious yogas, favourable for undertakings that require effort to bring to completion, promising that the goal is within reach. Reckoned from the summed longitude of Sun and Moon divided into twenty-seven parts, it advances as the lights separate through the month. In the panchanga it contributes its favourable, achievement-oriented quality to the reckoning of an auspicious time. These are the conventions of the calendar tradition, in which a benefic yoga such as Sadhya commends a moment for works meant to be carried through; the astronomical basis remains the simple arithmetic of the two luminaries' summed longitude over the lunar month.

Sadhya, that which can be accomplished, is grammatically a gerundive, a Sanskrit verbal form expressing what ought to or can be done, built from the same root, sadh, to accomplish or succeed, that gives Siddhi and Siddha their names; where those two describe a state already attained, Sadhya describes a goal still open and reachable through effort, a grammatical distinction that maps closely onto the difference in emphasis the tradition gives the three related yogas, attainment already achieved for Siddhi and Siddha, and attainment still to be worked for and genuinely possible for Sadhya.

The yoga is the limb of the panchanga that has no counterpart in the sky. Nothing about the day looks different when one ends and the next begins. 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. Sadhya is the arc from 280 degrees 00 minutes to 293 degrees 20 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 Sadhya is the twenty second 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 twenty second position, Shravana, is where it usually starts.

Sadhya sits among the eighteen yogas classed as favourable. That count matters more than it looks: with eighteen of twenty seven benign, the yoga is a weak filter on its own, and the classical muhurta writers use it as a tie breaker between candidate times rather than as a reason to reject one. A day is not made auspicious by its yoga alone.