According to the Hindu calendar, 15 days in the month of September-October is dedicated to our ancestor and it is called as Pitra Paksha. It generally falls in the Bhadrapada (hindi month). This year it starts on 23rd of september and ends on observed on 7th of October 2010. Mahalaya is the last day of Pitra Paksha.
Why it is Observed:
These 15 days are dedicated to our ancestors . Hindus believe that our lives are controlled by Navagraha / 9 planets and by ancestors. Hence, during the Pitra Paksha the ancestors are remembered and worshiped.It is believe that ancestors wait the whole year for these 15 days and they come on earth to give the blessing and positive energy to all members of the family. Auspicious occasions are not celebrated on these days.
How it is performed :
The person performing the Shradya and the person invited for the meal to be offered to brahmin should not take meals and avoid physical relations with a woman on the previous night of the day of Shradhya. As far as possible the Shradya should be performed on the ground floor of the residence. The venue of the Shradya ritual should be clean.During this period, special food is prepared and offered it to the brahmins.Clothes and some other items also donates on these days.Many people offered water to their ancestor daily and is called Tarpan.