Pitru Paksha is a waning fortnight given over to the ancestors, and it ends on the dark moon. Nothing new is begun during it.

The whole period runs from a full moon down to Mahalaya Amavasya, and the choice of the waning half is deliberate: the light is going, and so is the attention. Weddings and house purchases are postponed. It is one of the clearest cases anywhere of a culture reading the direction of the lunar cycle as the mood of a fortnight.