Srimad-Bhagavatam: Canto 7 - Chapter 1 - Verse 19
Sanskrit:
कुर्यादपरपक्षीयं मासि प्रौष्ठपदे द्विज: ।श्राद्धं पित्रोर्यथावित्तं तद्बन्धूनां च वित्तवान् ॥ १९ ॥
ITRANS:
kuryād apara-pakṣīyaṁmāsi prauṣṭha-pade dvijaḥśrāddhaṁ pitror yathā-vittaṁtad-bandhūnāṁ ca vittavān
Translation:
A brāhmaṇa who is sufficiently rich must offer oblations to the forefathers during the dark-moon fortnight in the latter part of the month of Bhādra. Similarly, he should offer oblations to the relatives of the forefathers during the mahālayā ceremonies in the month of Āśvina.*