Mahalaya is the beginning of ‘Devipaksha’ and the end of Pitru Paksha. On this day Goddess Durga arrives in Marta (Earth) from Sabrga (Heaven) as per Hindus scripture. That means the beginning day of Navarathri and Durgapuja.
Mahalayas Date & Time
According to the Hindu calendar, the Amavasya tithi of the month of Ashwin is counted as the day of Mahalaya. The Date 6th October, Wednesday 2021, Time is 6:32 PM on 5th October 5 to 5:09 PM on 6th October.
On this day very early in the morning through Chandi Path goddess Durga is called to come to Marta. And through this is the beginning of the ‘Devipaksha’. Pitr Tarpana is the other part of the Mahalaya.
According to the Puran, when the demon occupies the Trilok (Sabrga Lok, Marta Lok, & Patal Lok). And the gods, irritated by their oppression, took refuge in the goddess Parvati. Then Goddess Parvati took the form of the ten-armed Durga. And the gods worship Goddess Durga with all their might to subdue the demonic power. On the day of this Mahalaya, Goddess Durga freed Mahishasura, the demon lord, and freed the Trilok from the demons. For this reason, Goddess Durga is called Mahisasurmardini. That is the reason, Goddess Durga is worshipped as a force for 10 days from the day after the Mahalaya. As a Navaratri and Durga Puja.
The ancestors are honoured by remembering them through Pitar Tarpan. According to the scriptures, the tarpan is to free their soul by removing the faults of the ancestors.