What counts as an entry?
A rashi entry occurs when the Moon’s modeled sidereal ecliptic longitude crosses a multiple of 30°. A nakshatra entry occurs at one of 27 equal 13°20′ sectors. The table names the new sign or nakshatra at each change, and it states the Moon’s sector at the opening of the local month so the first dates are understandable.
The Positional Astronomy Centre’s Rashtriya Panchang explanation defines nakshatra from the Moon’s nirayana longitude. Its publication overview includes Moon transits into nirayana rashi and nakshatra among the almanac data. This calculator uses its own explicitly approximate sidereal model, so its minute of entry may differ from a national or regional almanac.
Why your local date may differ
An entry happens at one UTC instant. A Delhi reader and a California reader can see different calendar dates for that same crossing. The fixed offset changes the clock label and which entries fall inside the selected local month; it does not change the geocentric longitude. See the worked boundary example and calculation limits →