Indra

Indra is the twenty-sixth nityayoga, named for Indra, king of the gods. It is one of the auspicious yogas, favourable for undertakings connected with leadership, authority, honour, and success in worldly affairs. 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, sovereign quality to the reckoning of an auspicious time. These are the conventions of the calendar tradition, in which a benefic yoga bearing the name of the king of the gods commends a moment for matters of rank and command; the astronomical basis remains the simple arithmetic of the two luminaries' summed longitude over the lunar month.

Indra, king of the Vedic gods and lord of rain, thunder and war, occupies a curious position in later Hindu religious history: central and dominant in the earliest layer of the tradition, the Rigveda, where more hymns are addressed to him than to almost any other deity, he is gradually eclipsed in later Puranic literature by Vishnu, Shiva and the great goddesses as objects of devotional worship, becoming more a figure of myth and moral instruction, notably as a somewhat flawed and anxious ruler of heaven, than an object of temple cult. The twenty-sixth nityayoga's association with leadership and worldly success preserves something of Indra's older character as sovereign of the gods even as his independent worship faded.

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. Indra is the arc from 333 degrees 20 minutes to 346 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 Indra is the twenty sixth 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 sixth position, Uttara Bhadrapada, is where it usually starts.

Indra 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.