Understanding Tithi, Nakshatra & Panchanga: A Practical Modern Guide

In Nepal and across the Hindu world, opening a calendar (Patro) reveals much more than just the day of the week and month. Every day is accompanied by intricate notations: Tithi (तिथि), Nakshatra (नक्षत्र), Yoga (योग), Karana (करण), and Vaar (वार).

Collectively, these five elements form the Panchanga (पञ्चाङ्ग)—derived from the Sanskrit words Pancha (five) and Anga (limbs). For thousands of years, Vedic astronomers and astrologers have utilized this system to measure time, predict celestial events, and identify the most favorable moments (Muhurat) for human endeavors.

In this guide, we demystify the science behind each of the 5 limbs of Panchanga in clear, accessible terms.

What is Panchanga?

The Panchanga is essentially an astronomical ephemeris calculated from the relative positions and geometric angles between the Sun and the Moon as observed from Earth.

The five constituent limbs are:

  1. Vaar (वार): The solar weekday.
  2. Tithi (तिथि): The lunar day (angular separation of Sun and Moon).
  3. Nakshatra (नक्षत्र): The lunar constellation or asterism.
  4. Yoga (योग): The combined angular longitude of Sun and Moon.
  5. Karana (करण): Half of a Tithi.

Let us examine each limb in detail.

1. Tithi (तिथि): The Lunar Phase Day

While a solar day is measured from one sunrise to the next, a Tithi is measured by the changing angular distance between the Sun and the Moon.

  • The Moon revolves around the Earth in an elliptical orbit.
  • Every time the Moon moves 12 degrees ahead of the Sun in longitudinal distance, one Tithi elapses ($360^\circ \div 12^\circ = 30\text{ Tithis per lunar month}$).
  • Because the orbital speed of the Moon varies, the duration of a Tithi is not 24 fixed hours; a Tithi can last anywhere from 19 to 26 solar hours.

The Two Pakshas (Fortnights)

A lunar month consists of 30 Tithis divided into two 15-day fortnights (Paksha):
  1. Shukla Paksha (शुक्ल पक्ष - Bright / Waxing Half):
  • Begins right after the New Moon (Aunsi / Amavasya).
  • The Moon grows larger in illumination each night.
  • Culminates on the 15th Tithi: Purnima (पूर्णिमा - Full Moon).
2. Krishna Paksha (कृष्ण पक्ष - Dark / Waning Half):
  • Begins immediately after Purnima.
  • The illuminated disk of the Moon decreases each night.
  • Culminates on the 30th Tithi: Aunsi (औंसी - New Moon).

The 15 Tithi Names

Both fortnights share identical names for Tithis 1 through 14:
  1. Pratipada (प्रतिपदा / परेवा)
  2. Dwitiya (द्वितीया)
  3. Tritiya (तृतीया)
  4. Chaturthi (चतुर्थी)
  5. Panchami (पञ्चमी)
  6. Shashthi (षष्ठी)
  7. Saptami (सप्तमी)
  8. Ashtami (अष्टमी)
  9. Navami (नवमी)
  10. Dashami (दशमी)
  11. Ekadashi (एकादशी)
  12. Dwadashi (द्वादशी)
  13. Trayodashi (त्रयोदशी)
  14. Chaturdashi (चतुर्दशी)
  15. Purnima (Full Moon) / Amavasya (New Moon)
💡 NOTE
Why are Ekadashi dates so significant? The 11th lunar day (Ekadashi) of both Shukla and Krishna Paksha is revered as a sacred day of spiritual cleansing, prayer, and fasting (Upavasa), believed to balance the body's natural water cycles with gravitational lunar fluctuations.

2. Nakshatra (नक्षत्र): The 27 Lunar Constellations

While Western astrology emphasizes the 12 zodiac sun signs, Vedic astrology places primary emphasis on the 27 Nakshatras (Lunar Mansions).

As the Moon orbits the Earth against the background of distant stars, it completes a $360^\circ$ circle in approximately 27.3 days. Vedic astronomers divided this celestial path into 27 equal sectors of $13^\circ 20'$ each:

  • The Moon spends roughly one solar day traversing each Nakshatra.
  • Your Birth Star (Janma Nakshatra) is the constellation the Moon was traversing at the exact moment of your birth. In Vedic tradition, it defines your personality traits, subconscious tendencies, and Vedic name syllable.
Some prominent Nakshatras include:
  • Ashwini, Rohini, Pushya, Magha, Hasta, Swati, Anuradha, Shravana, and Revati.
  • Pushya Nakshatra, for instance, is considered universally auspicious for starting new enterprises, educational milestones, and major financial investments.

3. Yoga (योग): Angular Harmony

In astronomical calculation, Yoga represents the sum of the longitudes of the Sun and the Moon:
$$\text{Longitude of Sun} + \text{Longitude of Moon}$$

This sum is divided into 27 equal segments of $13^\circ 20'$ each, yielding 27 Yogas:

  • Certain Yogas are considered highly auspicious (e.g., Siddhi, Sadhya, Shubha, Brahma, Indra).
  • Others are considered malefic or unsuitable for inaugurating new ventures (e.g., Vishkambha, Atiganda, Shoola, Vyaghata, Vaidhriti).

Astrologers inspect the prevailing Yoga to determine whether a given day carries cooperative or discordant spiritual energy.

4. Karana (करण): Half of a Tithi

A Karana is exactly half of a Tithi ($6^\circ$ angular movement between Sun and Moon). Since there are 30 Tithis in a month, there are 60 Karanas in every lunar cycle:

  • There are 4 Fixed Karanas (occur only once a month around Amavasya): Shakuni, Chatushpada, Naga, and Kimstughna.
  • There are 7 Repeating Karanas: Bava, Balava, Kaulava, Taitila, Garija, Vanija, and Vishti (Bhadra).

Among these, the Vishti Karana (popularly known in Nepal as Bhadra / भद्रा) is traditionally avoided for travel, weddings, and signing vital business contracts.

5. Vaar (वार): The Seven Solar Weekdays

The seven days of the week correspond to the seven major visible celestial bodies recognized in ancient astronomy:

  1. Ravivaar (आइतबार): Sunday — Governed by the Sun (Surya)
  2. Somvaar (सोमबार): Monday — Governed by the Moon (Chandra)
  3. Mangalvaar (मङ्गलबार): Tuesday — Governed by Mars (Mangal)
  4. Budhavaar (बुधबार): Wednesday — Governed by Mercury (Budha)
  5. Brihaspativaar (बिहीबार): Thursday — Governed by Jupiter (Guru)
  6. Shukravaar (शुक्रबार): Friday — Governed by Venus (Shukra)
  7. Shanivaar (शनिबार): Saturday — Governed by Saturn (Shani)

How Panchanga Determines "Shubha Muhurat"

When a family in Nepal plans a wedding (Bibaha), sacred thread investiture (Bratabandha), or housewarming (Grihapravesh), a purohit evaluates all five limbs simultaneously:

  • Is the Tithi auspicious (e.g., avoiding Rikta Tithis like Chaturthi, Navami, Chaturdashi)?
  • Is the Nakshatra favorable to both the bride and groom?
  • Is the day free from Bhadra and malefic Yogas?
  • What is the Chandra Rashi (Moon's current zodiac sign) relative to the person's birth chart?

Modern tools like Mero Miti's Live Today Page calculate these five parameters in real-time, showing sunrise/sunset, current Tithi end-times, and active Moon signs with zero manual computation.

Conclusion

The Panchanga is a remarkable synthesis of celestial observation and cultural living. Far from being an outdated relic, it remains a vibrant framework that guides Nepal's agricultural rhythms, social celebrations, and spiritual observances every single day.