Ekadashi during Pitrupaksha; liberates ancestors from suffering

Indira Ekadashi is the Ekadashi of the dark fortnight of Ashwin (Bhadrapada Krishna in the Amanta calendar), and it is the only Ekadashi of the year that falls within Pitrupaksha. Its glory is told in the Padma Purana, where Krishna narrates to Yudhishthira the story of King Indrasena of Mahishmati. The sage Narada came to the king with a message from his late father, who was suffering in the realm of Yama for a lapse in a vow. On Narada's instruction Indrasena kept this Ekadashi with fasting and worship, offered shraddha to his ancestors on the day, and gave its merit to his father — who was at once released and ascended to Vaikuntha. For this reason Indira Ekadashi is kept especially for the liberation of one's ancestors. Devotees worship Lord Vishnu as Shaligram, offer tulsi, recite the Vrat Katha, and often perform shraddha for ancestors who died on an Ekadashi. The fast is broken on Dwadashi within the parana window after feeding brahmins.

Strict observers keep nirjala; others take fruit and milk once. Rice is especially avoided.