Amavasya and Purnima: Meaning, Timing Rules & Spiritual Observances
How New Moon (Amavasya) and Full Moon (Purnima) Tithis are decided, why dates vary by city, and which practices are traditionally linked to each.
By Vedic Astronomical Research Team ·
Amavasya (New Moon) and Purnima (Full Moon) are the two poles of the lunar month. Learn how they are calculated from Sun–Moon longitude, how festival dates are assigned, and common observances across India.
What is Amavasya?
Amavasya is the New Moon Tithi, when the Moon's longitude is closest to the Sun's longitude (near 0° separation). It closes Krishna Paksha and is associated with ancestor rites (Pitru Tarpan), certain fasts, and temple observances that vary by region and sampradaya.
What is Purnima?
Purnima is the Full Moon Tithi, when the Moon is about 180° from the Sun. Many major festivals — including Guru Purnima, Sharad Purnima, and Buddha Purnima — are anchored to this Tithi. Purnima also closes Shukla Paksha in the Purnimanta month system used widely in North India.
Why Amavasya/Purnima dates can differ from printed calendars
Printed panjikas sometimes use a fixed reference city. Online tools that recompute sunrise and lunar longitude for your city can assign the civil date differently when a Tithi begins late at night or ends shortly after sunrise. Rule of thumb: for most household observances, check which Tithi prevails at local sunrise, then confirm any special rule mentioned for that festival (for example, Nishita Kaal for some night rituals).
| Tithi | Sun–Moon separation | Paksha role | Common themes |
|---|---|---|---|
| Amavasya | ~0° / conjunction | Ends Krishna Paksha | Pitru rites, certain vratas, temple observances |
| Purnima | ~180° / opposition | Ends Shukla Paksha | Major festivals, charity, full-moon rituals |
Frequently Asked Questions
Q: Is Amavasya always inauspicious?
Not universally. Some activities are avoided, but ancestor offerings, specific temple rituals, and certain spiritual practices are traditionally performed on Amavasya.
Q: How do I find the next Amavasya or Purnima?
Use a daily Panchang or Hindu calendar view and look for Tithi names Amavasya or Purnima, or browse the festivals directory for Full Moon and New Moon linked observances.