It is true that mantra is a great medium for pray and offerings.
But love, attachment, feelings, sentiments, emotions, regards, Bhawana is a prime not mantras.
Ashwin Pitra Paksha Amvasya: Mon, 12 Sep 2015
The last day of the Shraddha Ceremony for the year 2015 is Mon, 12 October 2015 . This day is also known as Sarva Pitra Shraddha or Pitra Visarjan day. One can offer food and/or water to their ancestors to get their blessings.