Here is the list of Amavasya 2012 dates or No Moon days in 2012. Amavasya or No Moon day is an important day in Hindu calendar. Amavasya is considered inauspicious in many calendars in India but Tamil Panchang considers it as auspicious.
Check this article for Amavasya 2013 dates
As per North Indian Hindi calendars (Amavasyant calendars) followed in Himachal Pradesh, Uttar Pradesh, Madhya Pradesh, Chhattisgarh, Bihar, Jharkhand, Orissa, Rajasthan, etc..
Amavasya is the fifteenth day and marks the end of the first fortnight in a month whereas in other Panchang (Purnimant calendars) followed in Gujarat, Maharashtra, Karnataka and Andhra Pradesh, Amavasya it is the last day for a month. Here is the list
Amavasya in January 2012 – 23 January, Monday – Poush Amavasya in Marathi, Gujarati, Kannada, and Telugu calendars / Magh Amavasya in North Indian Hindi Panchang (Mauni Amavasya / Thai Amavasya in Tamil Nadu) — It is Somvati Amavasya as it falls on Somvar (Monday). Timings of Amavasya in January 2012.
Amavasya in February 2012 – 21 February, Tuesday – Magh Amavasya / Phalgun Amavasya. Time of Amavasya February 2012..
Amavasya in March 2012 – 22 March, Thursday – Falgun Amavasya / Chaitra Amavasya. Time of Amavasya in March 2012..
Amavasya in April 2012 – 21 April, Saturday – Chaitra Amavasya / Vaishakh Amavasya (Shani Amavasya).. Timings of Amavasya in April 2012
Amavasya in May 2012 – 20 May, Sunday – Vaishakh Amavasya / Jyeshta Amavasya (Shani Jayanti)… Time of Amavasya in May 2012
Amavasya in June 2012 – 19 June, Tuesday – Jyeshta Amavasya / Ashad Amavasya
Amavasya in July 2012 – 19 July, Thursday – Aadi Amavasai, Ashad Amavasya / Shravan Amavasya (Sitalagi Amavasya), Chukkala Amavasya, Gatari Amavasya, Bheemana Amavasya, Haryali Amavasya
Amavasya in August 2012 – 17 August, Friday – Shravan Amavasya / Adhik Bhadrapad Amavasya (Polala Amavasya, Pitori Amavasya, Pola)
Amavasya in September 2012 – 16 September, Sunday – Adhik Bhadrapada Amavasya / Nija Bhadrapad Amavasya
Amavasya in October 2012 – 15 October, Monday – Somvati Amavasya – Nija Bhadrapad Amavasya / Ashwin Amavasya – Mahalaya Amavasya
Amavasya in November 2012 – 13 November, Tuesday – Ashwina Amavasya / Kartik Amavasya – Diwali Amavasya
Amavasya in December 2012 – 13 December, Thursday – Kartik Amavasya / Margashirsh Amavasya