2003
- Thursday, 2 January 2003 · Margashirsha Amavasya
- Saturday, 1 February 2003 · Mauni Amavasya (Shani)
- Monday, 3 March 2003 · Magha Amavasya (Somvati)
- Tuesday, 1 April 2003 · Phalguna Amavasya (Bhaumvati)
- Thursday, 1 May 2003 · Chaitra Amavasya
- Saturday, 31 May 2003 · Vat Savitri Amavasya (Shani)
- Sunday, 29 June 2003 · Jyeshtha Amavasya
- Tuesday, 29 July 2003 · Hariyali Amavasya (Bhaumvati)
- Wednesday, 27 August 2003 · Shravana Amavasya
- Friday, 26 September 2003 · Mahalaya / Sarvapitri Amavasya
- Saturday, 25 October 2003 · Diwali (Lakshmi Puja) Amavasya (Shani)
- Sunday, 23 November 2003 · Kartika Amavasya
- Tuesday, 23 December 2003 · Margashirsha Amavasya (Bhaumvati)
2004
- Wednesday, 21 January 2004 · Mauni Amavasya
- Friday, 20 February 2004 · Magha Amavasya
- Saturday, 20 March 2004 · Phalguna Amavasya (Shani)
- Monday, 19 April 2004 · Chaitra Amavasya (Somvati)
- Wednesday, 19 May 2004 · Vat Savitri Amavasya
- Thursday, 17 June 2004 · Jyeshtha Amavasya
- Saturday, 17 July 2004 · Hariyali Amavasya (Shani)
- Sunday, 15 August 2004 · Adhika Shravana Amavasya
- Tuesday, 14 September 2004 · Shravana Amavasya (Bhaumvati)
- Thursday, 14 October 2004 · Mahalaya / Sarvapitri Amavasya
- Friday, 12 November 2004 · Diwali (Lakshmi Puja) Amavasya
- Saturday, 11 December 2004 · Kartika Amavasya (Shani)
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. Amavasya ends the dark half, so both month names are given.
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.