Why five parts share one page
Panchanga literally points to five limbs. The Rashtriya Panchang published by India's Positional Astronomy Centre names them vara, tithi, nakshatra, yoga, and karana. They mix a local day boundary with angular measures of the Sun and Moon. Calling them “today's panchanga” hides a choice: whether “today” means a civil date, a sunrise-to-sunrise day, or a specific clock instant.
| Vara | The weekday whose traditional day begins at local sunrise. |
|---|---|
| Tithi | Moon minus Sun longitude, divided into 30 portions of 12°. |
| Nakshatra | The Moon's sidereal longitude, divided into 27 portions of 13°20′. |
| Yoga | The sum of sidereal Sun and Moon longitudes, divided into 27 portions of 13°20′. |
| Karana | Moon minus Sun longitude, divided into 60 portions of 6°; two per tithi. |
Sunrise entry versus chosen instant
Many almanacs print the tithi and nakshatra that prevail at sunrise, and then the local time when each ends. That is a useful daily convention, but it does not mean the value remains unchanged until the next sunrise. The Moon moves quickly enough that a tithi or nakshatra may change during the day. Our calculator therefore gives a sunrise snapshot, the next change after sunrise, and a distinct snapshot at your chosen clock time.
Vara is local: the place determines sunrise, and a moment before sunrise can still belong to the preceding traditional weekday even when the civil date has advanced at midnight. At high latitude a sunrise may be absent on a civil date. The calculator will not invent one in that case; the chosen instant still has angular positions, but the selected date has no ordinary sunrise entry under this method.
Where ayanamsa enters
Tithi and karana depend on the difference between Moon and Sun longitudes. Subtracting the same ayanamsa from both leaves their difference unchanged. Nakshatra depends on the Moon's sidereal longitude and yoga on the sidereal Sun–Moon sum, so an ayanamsa choice can move their boundaries. This site uses its approximate Lahiri implementation, named in every result. A specialist panchanga may use a more precise ephemeris or a different convention and disagree near a boundary.
The two halves of a lunar month
From new moon toward full moon, the angular separation runs through fifteen waxing tithis, called Shukla Paksha. From full moon back toward new moon, the following fifteen are Krishna Paksha. Purnima and Amavasya are the final named tithis in their respective halves. Calendar-month naming and the assignment of observances differ by region, so this angular calculator does not try to infer festival dates.
Names and calculation source
The names follow the Rashtriya Panchang's published English transliteration table. Solar and lunar vectors come from the site's bundled Astronomy Engine 2.1.19. Sunrise uses the engine's modeled solar disc and standard atmospheric refraction at the given coordinates. The user enters a fixed UTC offset because the page does not have a historic time-zone database; daylight-saving clock changes within the date are not modeled.