The entire pañcāṅga is derived from just two numbers — the Sun's and the Moon's longitude on the ecliptic. Drag them, or play a month, and watch every limb follow.
Bhoganśa — the arc a body has travelled along the ecliptic, 0°–360°.
The tithi is the almanac's basic day-unit — festivals and vrats are fixed by it.
The almanac names each civil day by the tithi running at sunrise — which is why a tithi can skip or repeat on wall calendars. For today's actual pañcāṅga, see hinducalendar.app.
Longitudes on this page are nirayana (sidereal, Lahiri ayanāṃśa) — measured from a fixed point among the stars, as the pañcāṅga requires; 0° is not the vernal equinox.