SB 7.14.19

kuryād apara-pakṣīyaṁ
 māsi prauṣṭha-pade dvijaḥ
śrāddhaṁ pitror yathā-vittaṁ
 tad-bandhūnāṁ ca vittavān
Word for word: 
kuryāt — one should perform; apara-pakṣīyam — during the fortnight of the dark moon; māsi — in the month of Āśvina (October-November); prauṣṭha-pade — in the month of Bhādra (August-September); dvijaḥ — twice-born; śrāddham — oblations; pitroḥ — unto the forefathers; yathā-vittam — according to one’s means of income; tat-bandhūnām ca — as well as relatives of forefathers; vitta-vān — one who is sufficiently rich.
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.*