Somvati Amavasya is the No Moon day that falls on Somavar or Monday. On Somvati Amavasya day, Punya Snan or holy dip is performed by devotees in Haridwar and Prayag Triveni Sangam. Ganga Snan is considered as utmost auspicious during Somvati.
Tens of thousands of devotees converge along the river banks of Ganga on Amavasya. The congregation of devotion really looks like Maha Kumbh Mela Amavasya snan. In 2021, Somvati Amavasya of 12 April 2021 has great significance as it falls during Kumbh Mela.
Hindus believe that observing Somvati Amavasya vrat would take them away from sorrows and sins in their life and makes them reach the Vishnu Loka or salvation. Somvati Amavasya Tharpan and shraddh rites to dead ancestors assure our pitru devtas rest in peace. Married women pray to a peepal tree (fig tree) for the longevity of their husbands and children.
Here is the Sankalpa Mantram to chant during Somvati Amavasya Puja.