Why and when do families do the Satyanārāyaṇa Kathā?

it is a simple pūjā of Viṣṇu as the Lord of Truth, done on Pūrṇimā or to give thanks at a new beginning — a wedding, a new home, a new job.

Satyanārāyaṇa means “Nārāyaṇa who is Truth”. The pūjā and its five short chapters of stories are traditionally said to come from the Skanda Purāṇa. The stories all carry one message: keep your word to God and to others, do not neglect a promised offering, and share prasāda humbly.

It is usually done on Pūrṇimā, Ekādaśī or Saṅkrānti, or after a happy event such as a wedding, gṛha-praveśa, a birth or recovery. A priest or an elder can conduct it, or the family can read the kathā together. The setup includes a decorated platform with a kalaśa, Viṣṇu’s picture or Śāligrāma, tulasī, bananas, pañcāmṛta and the special prasāda (śīrā or pañjīrī made with wheat or semolina, ghee, sugar and banana).

The most important part is the last: everyone, including neighbours and guests, receives the prasāda.

Source: Skanda Purāṇa (as traditionally attributed) · Common days: Pūrṇimā, Ekādaśī, Saṅkrānti

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