Somvati Amavasya, also known as Ama Somvar Vrata, is observed on Amavasya or No Moon day which falls on Somvar or Monday. In 2012, there will be two Somvathi Amavasya days. The first Somvati Amavasya date is January 23, 2012 and the second one is on October 15, 2012.
Devotees keep fasting during Somvati Amavasya and break their fast after performing Shiva Puja and Chandra Pooja. People perform Punya Snan on Amavasya and offer pinda daan or Pitru tharpan rituals on this day. A large number of devotees throng to the river banks of Ganga, Yamuna, Mahanadi, Godavari,Krishna and Cauvery to perform Punya Snan and Tharpan.
January 2012 Amavasya is Magh Amavasya as per North Indian calendars and Pousha Amavasya as per other Hindu calendars.
October 2012 Amavasya is Ashwin Amavasya in North Indian Hindi calendars and Nija Bhadrapad Amavasya as per Marathi, Gujarati, Kannada & Telugu calendars. It is also referred to as Mahalaya Amavasya / Sarva Pitru Amavasya.