2019
- Saturday, 5 January 2019 · Margashirsha Amavasya (Shani)
- Monday, 4 February 2019 · Mauni Amavasya (Somvati)
- Wednesday, 6 March 2019 · Magha Amavasya
- Friday, 5 April 2019 · Phalguna Amavasya
- Saturday, 4 May 2019 · Chaitra Amavasya (Shani)
- Monday, 3 June 2019 · Vat Savitri Amavasya (Somvati)
- Tuesday, 2 July 2019 · Jyeshtha Amavasya (Bhaumvati)
- Thursday, 1 August 2019 · Hariyali Amavasya
- Friday, 30 August 2019 · Shravana Amavasya
- Saturday, 28 September 2019 · Mahalaya / Sarvapitri Amavasya (Shani)
- Monday, 28 October 2019 · Diwali (Lakshmi Puja) Amavasya (Somvati)
- Tuesday, 26 November 2019 · Kartika Amavasya (Bhaumvati)
- Thursday, 26 December 2019 · Margashirsha Amavasya
2020
- Friday, 24 January 2020 · Mauni Amavasya
- Sunday, 23 February 2020 · Magha Amavasya
- Tuesday, 24 March 2020 · Phalguna Amavasya (Bhaumvati)
- Wednesday, 22 April 2020 · Chaitra Amavasya
- Friday, 22 May 2020 · Vat Savitri Amavasya
- Sunday, 21 June 2020 · Jyeshtha Amavasya
- Monday, 20 July 2020 · Hariyali Amavasya (Somvati)
- Wednesday, 19 August 2020 · Shravana Amavasya
- Thursday, 17 September 2020 · Mahalaya / Sarvapitri Amavasya
- Friday, 16 October 2020 · Adhika Ashwina Amavasya
- Sunday, 15 November 2020 · Diwali (Lakshmi Puja) Amavasya
- Monday, 14 December 2020 · Kartika Amavasya (Somvati)
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.