Nakshatraनक्षत्र

A nakshatra, or lunar mansion, is one of 27 equal segments of the zodiac, each spanning 13°20' (360° divided by 27). The set is the oldest layer of Indian astronomy — the Moon, moving about 13.2° per day, transits roughly one nakshatra each day, which is what makes them a natural lunar calendar. Each carries a name, a ruling planet, and a presiding deity.

The nakshatra is computed from the sidereal longitude of the Moon — the tropical position from the Swiss Ephemeris with the Lahiri ayanamsa subtracted — divided into 13°20' bands. For the panchanga, the nakshatra reported for a date is the one occupied by the Moon at sunrise, and its end time is the moment the Moon’s longitude next crosses a band boundary, found by bisection and shown in the location’s timezone.

The nakshatra also reaches beyond the daily almanac. In a natal chart, the Moon’s nakshatra at birth — and the quarter (pada) within it — anchors the Vimshottari dasha sequence, the timeline of planetary periods. That dependence is one reason SahiKundli uses sidereal positions throughout: a tropical reckoning would place the Moon in the wrong nakshatra by roughly one full mansion.