SB 7.14.19
kuryad apara-paksiyam
masi praustha-pade dvijah
sraddham pitror yatha-vittam
tad-bandhunam ca vittavan
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
A brahmana who is sufficiently rich must offer oblations to the forefathers during the dark-moon fortnight in the latter part of the month of Bhadra. Similarly, he should offer oblations to the relatives of the forefathers during the mahalaya ceremonies in the month of Asvina.*