Decoding the Panchanga: How Nepali Astrologers Calculate Time
The Bikram Sambat calendar is not simply a list of days; it is a complex astronomical document known as a "Panchanga." The word Panchanga translates to "Five Limbs," representing the five fundamental elements of time calculated by Hindu Vedic astrologers.
The Five Limbs of Time
- Tithi (Lunar Day): The angular relationship between the Sun and the Moon. A Tithi can vary between 19 and 26 hours. All Nepali festivals (like Dashain) are determined by the Tithi, not the solar date.
- Vaar (Weekday): The standard 7-day week, named after celestial bodies (e.g., Ravi-vaar for Sunday/Sun, Som-vaar for Monday/Moon).
- Nakshatra (Lunar Mansion): The 27 sectors along the ecliptic. The moon travels through one Nakshatra approximately every day.
- Yoga (Luni-Solar Day): Calculated by adding the longitude of the Sun and the Moon, divided into 27 unique segments.
- Karana (Half Lunar Day): Exactly half of a Tithi.
The Role of the Panchanga Nirnayak Samiti
Because these five elements rely on the physical orbits of planets, they do not perfectly align with 24-hour clocks. This is why a Tithi might start at 2:00 PM on a Tuesday and end at 1:15 PM on a Wednesday.
The Nepal Panchanga Nirnayak Samiti (Calendar Determination Committee) uses advanced mathematics and historical Vedic texts to calculate these precise alignments for the entire year, resulting in the official "Patro" (Calendar).
Modern Access
In the past, you had to buy a physical paper Patro from a local market to know these dates. Today, we have digitized this massive astronomical dataset. You can explore the modern application of the Panchanga through our Digital Monthly Patro, available globally.