Dhruva

Dhruva is the twelfth nityayoga, and its name means fixed, firm, and constant, the same word names the pole star, Dhruva, the unmoving point of the sky. It is one of the auspicious yogas, favourable for undertakings meant to be permanent and unshakeable, such as laying foundations and making lasting commitments. Reckoned from the summed longitude of Sun and Moon divided into twenty-seven parts, it advances as the lights draw apart. In the panchanga it lends its quality of fixity to the reckoning of an auspicious moment. These are the conventions of the calendar tradition, which fixes the character of each yoga; here the very name evokes the steadfastness the tradition seeks for enduring works.

Because dhruva names both this yoga and the pole star, the word carries an unusually concrete astronomical referent compared with most of the twenty-seven, whose names describe abstract qualities, states or deities rather than a specific fixed point in the sky; the pole star's genuine celestial fixity, its position scarcely changing while the rest of the sky wheels around it nightly, gives Dhruva's association with permanence and reliability an observational grounding rather than a purely symbolic one. The pole star Dhruva is also the subject of a well-known devotional legend, the boy sage whose steadfast penance won him his fixed place in the heavens, a story frequently invoked wherever the theme of unwavering constancy is illustrated in later religious literature.

A yoga is arrived at by addition, which sets it apart from every other reckoning in the almanac. 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. Dhruva is the arc from 146 degrees 40 minutes to 160 degrees 00 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 Dhruva is the twelfth 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 twelfth position, Uttara Phalguni, is where it usually starts.

Dhruva 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.