2030
- Friday, 4 January 2030 · Margashirsha Amavasya
- Saturday, 2 February 2030 · Mauni Amavasya (Shani)
- Monday, 4 March 2030 · Magha Amavasya (Somvati)
- Tuesday, 2 April 2030 · Phalguna Amavasya (Bhaumvati)
- Thursday, 2 May 2030 · Chaitra Amavasya
- Saturday, 1 June 2030 · Vat Savitri Amavasya (Shani)
- Sunday, 30 June 2030 · Jyeshtha Amavasya
- Tuesday, 30 July 2030 · Hariyali Amavasya (Bhaumvati)
- Wednesday, 28 August 2030 · Shravana Amavasya
- Friday, 27 September 2030 · Mahalaya / Sarvapitri Amavasya
- Saturday, 26 October 2030 · Diwali (Lakshmi Puja) Amavasya (Shani)
- Monday, 25 November 2030 · Kartika Amavasya (Somvati)
- Tuesday, 24 December 2030 · Margashirsha Amavasya (Bhaumvati)
2031
- Thursday, 23 January 2031 · Mauni Amavasya
- Friday, 21 February 2031 · Magha Amavasya
- Sunday, 23 March 2031 · Phalguna Amavasya
- Monday, 21 April 2031 · Chaitra Amavasya (Somvati)
- Wednesday, 21 May 2031 · Vat Savitri Amavasya
- Thursday, 19 June 2031 · Jyeshtha Amavasya
- Saturday, 19 July 2031 · Hariyali Amavasya (Shani)
- Monday, 18 August 2031 · Shravana Amavasya (Somvati)
- Tuesday, 16 September 2031 · Adhika Bhadrapada Amavasya (Bhaumvati)
- Thursday, 16 October 2031 · Mahalaya / Sarvapitri Amavasya
- Friday, 14 November 2031 · Diwali (Lakshmi Puja) Amavasya
- Sunday, 14 December 2031 · Kartika Amavasya
How the date is fixed
Every new-moon day, taken as the day on which Amavasya is running at sunrise. One that falls on a Monday is called Somvati, on a Tuesday Bhaumvati, and on a Saturday Shani Amavasya.
About
Amavasya is the tithi in which the Moon's longitude returns to the Sun's, closing the dark half and, in amanta reckoning, the month itself. It is the tithi of the pitris, and tarpana for ancestors is its regular observance; the aparahna (afternoon) is the governing period for shraddha, so the day whose afternoon carries Amavasya is chosen. Several named Amavasyas stand out: Sarva Pitru Amavasya ending Pitru Paksha, Diwali on Ashwina Amavasya, Mauni Amavasya in Pausha, and any Amavasya on a Monday (Somvati) or Saturday (Shani). Solar eclipses can only occur on Amavasya, which is why eclipse rules are tied to it.
How it is observed
Tarpana for ancestors in the afternoon, river bathing on Somvati and Mauni Amavasya, and lamps at dusk.