As per Hindu religion every Amavasya is equally important to worship our ancestors but Amavasya of Ashwin Maas is quite fruitful. It is known as Sarvpitri Amavasya or Mahalaya. It is observed on the last day of Shardha / Pitra Paksh. It is basically observed to bid adieu to our ancestors. Find out more about Sarvpitri Amavasya, importance and puja vidhi here in this video.