Mahalaya, Mahalaya Amavasya is the last day of Pitru Paksha. In 2014, Mahalaya date is September 24. On this day, In Bengal, Durga Puja is started.
Devotees welcome Goddess Durga or Mahishasura Mardhini to their homes on this day.
The six-day long Durga Puja celebrations will be started on Mahalaya. In other parts of India, people observe Navratras from Pratipada in Ashwin month.
On Mahalaya, people perform ritual bath or take holy dip in the river Ganga and observe ritual of Torpon. Durga idols eyes are painted on this day.
This day is also observed as Mahalaya Amavasya or Sarva Pitru Amavasya.
It is the most auspicious day to perform Pitru Shraddh rituals. The dead ancestors are offered Panda Daan and other shraddh rituals on this day.