If for three consecutive years the offerings are not made to the dear departed then the dead gets vehement, so to calm them these offerings are made. Tripindi is also done in case of unnatural death. In this type of death family member heard death people sound, they come on dream, their images comein sight or mirror.
Best Time for Tripindi Shradh or Tripindi Death Anniversary Ritual: This rite can be performed on the important months like 5th, 8th, 9th, 10th, 11th, 12th and 2nd month of the Hindu calendar and on 5th, 8th, 11th, 13th, 14th, 30th in the dark half of the lunar month is the lunar day or Sunday. But if fierce-day agony is experienced then Tripindi Shradha must be performed immediately. This measure is mentioned in "Godayatra Viveka-Darsha".
Remedy as Tripindi Shradha: Tripindi Shradh removes the entire bad omen that one has experienced in past. Tripindi Shradh liberates the souls of deceased and thence bringing peace in life of family members.