Amavasya is the new moon day in the Hindu lunar calendar, when the moon is completely eclipsed from earthly sight. Occurring at the transition between the waning Krishna Paksha and the waxing Shukla Paksha, it concludes the month in the Amanta reckoning and divides the month in the Purnimanta reckoning.
Because the day is governed by ancestral spirits (Pitrus), it is considered sacred for offering oblations (tarpana), performing shraddha rituals, and distributing food to the needy. Devotees often observe a partial or complete fast and take holy baths in sacred rivers like the Ganga or Yamuna.
Certain monthly Amavasyas hold heightened religious prominence throughout the year, such as Mahalaya Amavasya during Pitru Paksha, Mauni Amavasya in Magha, and Somvati Amavasya whenever the new moon coincides with a Monday.