What Is Amavasya and Purnima? Meaning, Difference & Dates
Amavasya vs Purnima explained: New Moon vs Full Moon tithis, why dates vary by city, Ashadha Purnima, and observances across India.
By Vedic Astronomical Research Team ·
What is Amavasya and Purnima? Amavasya is the New Moon tithi; Purnima is the Full Moon tithi. Compare Amavasya vs Purnima, how each is calculated from Sun–Moon longitude, and named Purnimas such as Ashadha Purnima (Guru Purnima).
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 (Ashadha 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.
Amavasya vs Purnima: the difference
Amavasya vs Purnima is a New Moon vs Full Moon contrast — they never fall on the same civil day as each other in a normal lunar month. - Amavasya: conjunction (~0°). Dark fortnight ends. Pitru rites, some vratas, Diwali Amavasya in Kartika. - Purnima: opposition (~180°). Bright fortnight ends. Charity, full-moon festivals, many regional fairs. A lunar month has 30 tithis. Purnima is the 15th of Shukla Paksha; Amavasya is the 15th of Krishna Paksha (tithi 30 in the 30-tithi count). If someone searches both words together, they usually want this comparison, not a single combined festival.
| Point | Amavasya (New Moon) | Purnima (Full Moon) |
|---|---|---|
| Sun–Moon angle | ~0° / conjunction | ~180° / opposition |
| Paksha role | Ends Krishna Paksha | Ends Shukla Paksha |
| Sky | Moon not visible | Moon fully illuminated |
| Typical observances | Pitru tarpan, some vratas, Kartika Amavasya | Guru Purnima, Sharad Purnima, Buddha Purnima |
| Also called | Amasya / Amavas / New Moon day | Poornima / Full Moon day |
Ashadha Purnima (Guru Purnima)
Ashadha Purnima — also written Ashadh, Aashadha, or sometimes searched as “amosha purnima” — is the Full Moon of the Hindu month Ashadha (June–July). It is widely observed as Guru Purnima, honouring teachers and the sage Vyasa. It is a Purnima, not an Amavasya. Check the Hindu calendar or festivals page for the Gregorian date each year, because the civil date follows the tithi at the local sunrise or the specified night window.
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).
- Amavasya and Purnima are opposite tithis, about 15 lunar days apart.
- Use a city-aware Panchang when a tithi straddles midnight.
Frequently Asked Questions
Q: What is Amavasya and Purnima?
Amavasya is the New Moon tithi (Sun and Moon nearly aligned). Purnima is the Full Moon tithi (about 180° apart). They are the two poles of the Hindu lunar month.
Q: What is the difference between Amavasya and Purnima?
Amavasya vs Purnima: Amavasya ends the dark fortnight and is a New Moon; Purnima ends the bright fortnight and is a Full Moon. They are not the same day and they carry different ritual traditions.
Q: What is Ashadha Purnima?
Ashadha Purnima is the Full Moon in the month of Ashadha, observed as Guru Purnima. It is sometimes misspelled in search as Ashada or amosha purnima.
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.