How the Hindu Panchang Works: Tithi, Nakshatra, and Festival Calculations Explained

The word *Panchang* originates from Sanskrit *Pancha* (five) and *Anga* (limbs). Unlike the purely solar Gregorian calendar which has 365.242 days per year, the traditional Indian calendar is **Luni-Solar**--synchronizing both the moon's phases and the sun's apparent path. ### The Five Limbs of Panchang 1. **Tithi (Lunar Day)**: The angular distance between the Sun and Moon increasing by 12 degrees. A lunar month has 30 tithis (15 Shukla Paksha / Waxing and 15 Krishna Paksha / Waning). 2. **Vara (Solar Weekday)**: Ravivara (Sun), Somavara (Moon), Mangalavara (Mars), Budhavara (Mercury), Guruvara (Jupiter), Shukravara (Venus), and Shanivara (Saturn). 3. **Nakshatra (Lunar Mansion)**: The 27 ecliptic star constellations through which the Moon traverses roughly every 27.3 days. 4. **Yoga (Luni-Solar Combination)**: 27 specific angular relationships between the longitude of the Sun and Moon. 5. **Karana (Half-Tithi)**: Half of a Tithi (60 Karanas in a lunar month). ### Why Do Indian Festival Dates Shift Annually? Because 12 lunar months total approximately 354 days (11 days shorter than the solar year), an extra intercalary month called **Adhik Maas (Purushottam Maas)** is introduced roughly every 32.5 months to realign the lunar calendar with the solar agricultural seasons.