The Tithi, or lunar day, is the first and arguably most fundamental of the five limbs of time (Panchanga) in Vedic Astrology. It governs the energetic quality of a day based on the constantly shifting angular relationship between the Sun and the Moon. In the science of Muhurta, understanding the Tithi is essential because the Moon represents the mind, emotions, public pulse, and flow of nourishment—critical factors that influence the initial momentum and eventual success of any endeavor. The deliberate use of Tithi for lunar day selection is a core principle of tithi muhurta. 

It is not enough to simply choose a random date; one must choose a quality of time, and that quality is largely dictated by the Moon’s phase and its specific 12-degree elongation from the Sun. This chapter explores the profound significance of the Tithi, its calculation, its inherent auspiciousness, and how its strategic use ensures a strong foundation for every new beginning.

The Opinion: Tithi Defines the Emotional Foundation of an Event

The Tithi (or Moon day) provides the baseline psychological and environmental harmony for any Muhurta. It defines whether the moment is naturally one of growth, stability, joy, or contraction.

The Reason: The Sun-Moon Synergy

Why is the Tithi so influential? Because it measures the synergy between the two most vital luminaries:

• The Sun (Surya): Represents the soul, vitality, authority, and Prakriti (the cosmic spirit).
• The Moon (Chandra): Represents the mind, emotions, receptivity, and Manas (the terrestrial consciousness).

The Tithi is a measure of how aligned or opposed these two forces are. When the Moon is far from the Sun (near the Full Moon), the Tithi supports fulfillment and clarity. When the Moon is near the Sun (New Moon), the Tithi is better for spiritual retreat and letting go. A careful tithi auspicious selection ensures the emotional and mental current of the event aligns with its intended outcome.

The Example: Starting a Project During the Waxing Moon

Imagine launching a long-term artistic project:

• Choosing an Auspicious Tithi (e.g., Panchami): This Tithi, especially during the waxing cycle, is associated with wealth and fullness. The lunar phases are supportive of creative expansion, ensuring the project attracts resources and maintains emotional momentum.
  
• Avoiding an Inauspicious Tithi (e.g., Chaturthi): This Tithi is considered Rikta (barren or empty) and is associated with obstacles. Starting the project then preloads it with a subtle tension and susceptibility to hurdles.

The Restatement: Timing the Cosmic Tide

Therefore, the Tithi is the primary indicator of the cosmic tide. By selecting an appropriate Tithi for muhurta, we are ensuring that the emotional and foundational energy of the moment is conducive to the venture’s growth and success.

The Calculation and Structure of the Tithi

To understand the tithi muhurta system, one must grasp the astronomical basis of the lunar day selection.

The Astronomical Basis

A Tithi is a time unit based on the difference in longitudinal angle (lambda) between the Moon (lambda_m) and the Sun (lambda_s).

Tithi = frac{(lambda_m – lambda_s)}{12 circ}

• A Tithi is completed when the longitudinal difference between the Moon and the Sun is exactly 12 circ (or a multiple of 12 circ).
  
• Since the Moon moves faster than the Sun, the time it takes for the 12 circ difference to accrue is approximately 20 to 27 hours. Tithis are therefore not equal to a calendar day. They can start or end at any time of day or night.

The Two Pakshas (Lunar Fortnights)

The 30 Tithis are divided into two primary cycles, reflecting the fundamental lunar phases:

1. Shukla Paksha (The Bright Half / Waxing Moon)

• Tithis 1 to 15 (Amavasya to Purnima): The Moon is increasing in light.
• Energy Quality: Characterized by growth, gain, manifestation, and clarity.
• Muhurta Application: Highly favored for all auspicious timing, new beginnings, ceremonies, initiation, and activities focused on acquisition or expansion.

2. Krishna Paksha (The Dark Half / Waning Moon)

• Tithis 1 to 15 (Purnima to Amavasya): The Moon is decreasing in light.
• Energy Quality: Characterized by withdrawal, reflection, release, and contraction.
• Muhurta Application: Better suited for concluding matters, clearing debts, spiritual practice, demolition, cutting off ties, and activities focused on reduction or destruction. Generally avoided for new business or marriage.

The 15 Tithis and Their Specific Auspiciousness

The 15 Tithis (which repeat twice to make 30) are categorized based on their inherent nature, a crucial step in lunar day selection. These categories guide the selection process based on the desired outcome of the event.

Tithi Name	Number	Category	Ruling Deity	Auspiciousness & Usage
Pratipada	1st	Nanda (Joyous)	Agni (Fire)	Good for planting, new friendships, rituals. Avoid for travel.
Dwitiya	2nd	Bhadra (Auspicious)	Brahma	Excellent for laying foundations, starting educational, and starting major work.
Tritiya	3rd	Jaya (Victorious)	Gauri (Parvati)	Good for courage, cutting, and conquering enemies. Favorable for ceremonies.
Chaturthi	4th	Rikta (Barren)	Ganesha	Highly inauspicious for all beginnings. Good for confronting obstacles or destructive acts.
Panchami	5th	Purna (Full)	Naga (Serpent)	Best for medicine, giving/taking loans, and seeking wealth/prosperity. Highly favorable.
Shashti	6th	Nanda (Joyous)	Kartikeya	Good for meeting superiors, travel, and creative work.
Saptami	7th	Bhadra (Auspicious)	Sun (Surya)	Favorable for journeys, vehicle purchase, legal matters, and public affairs.
Ashtami	8th	Jaya (Victorious)	Shiva	Good for administration, physical training, and challenging endeavors.
Navami	9th	Rikta (Barren)	Durga	Inauspicious for major ceremonies. Better for defense, weapons, and destruction of enemies.
Dashami	10th	Purna (Full)	Yama	Highly auspicious for all work, especially matters of tradition, religion, and long-term gain.
Ekadashi	11th	Nanda (Joyous)	Vishwa Deva	Extremely auspicious for religious rites, fasting, spiritual initiation, and worship.
Dwadashi	12th	Bhadra (Auspicious)	Vishnu	Good for religious acts, establishing contacts, and consecration.
Trayodashi	13th	Jaya (Victorious)	Kama (Desire)	Favorable for relationships, quick results, and acts of passion.
Chaturdashi	14th	Rikta (Barren)	Shiva	Strictly avoided for most work. Better for severe, intense rituals or concluding matters.
Purnima/Amavasya	15th	Purna (Full)	Moon/Pitra	Purnima is excellent for spiritual work; Amavasya (New Moon) is inauspicious for all beginnings.

The Critical Veto: Rikta Tithis

The Rikta Tithis (4th, 9th, 14th) are the primary “veto” factors in Tithi selection. The word Rikta means “empty” or “barren.” Any action initiated on these days is considered likely to be frustrated, meet obstacles, or result in emptiness. Tithi auspicious selection begins by ruling out these three days.

The Purna Tithis and Their Nuances

The Purna Tithis (5th, 10th, 15th) are generally excellent, signifying fulfillment and wealth. However, the Full Moon (Purnima) and New Moon (Amavasya) require specific attention:

• Purnima (Full Moon): Excellent for emotional, artistic, and spiritual work. Highly charged day. Generally good for Muhurta, provided other factors align.
• Amavasya (New Moon): The time when the Sun and Moon are conjunct. The Moon (mind) is “dark” and lacking strength. Universally avoided for any new beginning (marriage, business, travel) as it portends a weak foundation and lack of mental clarity.

Tithi in Action: Strategic Muhurta Applications

The tithi muhurta system integrates the Tithi’s energy with the specific goal of the event. Here is how lunar day selection is applied to major life events:

1. For Marriage and Relationships (Vivah Muhurta)

• Goal: Stability, growth, and happiness.
• Tithi Preference: Shukla Paksha (Waxing Moon) Dwitiya (2nd), Tritiya (3rd), Panchami (5th), Saptami (7th), Dashami (10th), Ekadashi (11th), and Dwadashi (12th).
• Reason: These Tithis are Nanda, Bhadra, or Jaya and occur during the Moon’s phase of increasing light, supporting the longevity and growth of the union.
• Strict Avoidance: Rikta Tithis (4, 9, 14), Amavasya (New Moon).

2. For Starting a Business or Job (Vyapar/Karma Arambha)

• Goal: Financial gain, expansion, and continuity.
• Tithi Preference: Dashami (10th) and Panchami (5th) are highly favored for wealth. Ekadashi (11th) is also excellent. Must be in the Shukla Paksha.
• Reason: Purna Tithis (like 5th and 10th) are associated with fullness and wealth. The waxing phase supports expansion and increasing revenue.
• Strict Avoidance: Rikta Tithis (4, 9, 14), Chaturdashi (14th – for intense conclusion), and Amavasya.

3. For Starting Construction or Griha Pravesh (House Activities)

• Goal: Permanence, comfort, and security.
• Tithi Preference: Tritiya (3rd), Panchami (5th), Saptami (7th), Dashami (10th), or Dwadashi (12th).
• Reason: These Tithis are stable and growth-oriented, helping to settle the energy of the home.
• Strict Avoidance: Chaturthi (4th), Navami (9th), and Amavasya.

4. For Cutting, Surgery, or Concluding Matters

• Goal: Successful removal, quick healing, or conclusion.
• Tithi Preference: Krishna Paksha (Waning Moon) Tithis, particularly Pratipada (1st), Ashtami (8th), and Trayodashi (13th). Sometimes the Rikta Tithis are used for aggressive, destructive acts (like paying off debts or surgery), though this is advanced and carefully monitored.
• Reason: The waning Moon supports reduction, closure, and removal, aligning the mind with the idea of letting go.

Common Tithi Afflictions and Exceptions

While the Rikta Tithis are the primary fault, the tithi muhurta system includes specific afflictions and exceptions that further refine the time calculation.

Tithi Doshas (Lunar Day Faults)

• Purna/Amavasya Dosha: Although Purnima is a Purna Tithi, the tithi sandhi (the exact moment of the Tithi’s change) around the Full and New Moon is considered weak. The 15th Tithi (Purnima) should be avoided entirely for any event requiring longevity or stability.
  
• Tithi Kshaya and Vriddhi (Loss and Gain): Sometimes a Tithi is too short (Kshaya, or loss) or too long (Vriddhi, or gain). A Kshaya Tithi is inauspicious as it lacks full vigor, while a Vriddhi Tithi is generally favorable.
  
• Dagda Tithis (Combustible Tithis): Specific days of the week combined with specific Tithis are considered “burnt” or weak and are to be avoided. For instance, the 12th Tithi on a Friday, or the 11th Tithi on a Saturday. This shows how Tithi is integrated with the Vara (weekday).

Integration with Other Panchanga Limbs

The Tithi is never analyzed in isolation. It is the combination of Tithi with the other limbs that creates the final auspicious quality:

• Yoga (Combination): Certain Tithis combined with specific Nakshatras form highly auspicious Yogas like Siddhi Yoga or Amrita Siddhi Yoga, which can often override minor Tithi flaws.
  
• Karana (Kinetic Impulse): A Tithi is only complete if its Karana is not Vishti (Bhadra). A highly auspicious Tithi is still rejected if the time falls under the malefic Vishti Karana.

The mastery of tithi muhurta is realizing that while the Tithi provides the emotional framework, it is the integration with the Nakshatra (body of time) and the Vara (will of time) that forms the complete, reliable Muhurta.

Conclusion: The Precision of the Moon Day

The Tithi is the celestial metronome for every new beginning. In the meticulous science of muhurta, the lunar day selection acts as the initial and most potent filter for determining the quality of time. By consciously observing and applying the principles of the Panchanga Vedic calendar, particularly the auspicious and inauspicious qualities of the lunar phases, we are aligning the mental, emotional, and foundational energy of our actions with the universe’s rhythmic current.

Choosing a propitious Tithi is the first strategic step in ensuring that our efforts, our relationships, and our ventures are initiated with clarity, growth, and the highest potential for success, avoiding the pitfalls of cosmic imbalance. The precision of the tithi muhurta system proves that in the vastness of time, the Moon’s subtle dance holds the key to our earthly fortune.