Q. Is it better to say the sheva brachoth on the last day in the middle of the meal or is it better after birchat hamazon when already after the shkiah?

A. Horav Shlomo Miller’s Shlit’a opinions is that when we find ourselves close to the shkia on the last day of sheva brochos, the participants should stop eating and proceed with benching and sheva brochos, then continue and finish the meal. The brochos recited anew on the food are not considered as unnecessary (brocho sheino t’zricho), since birchas hamazon was recited for a valid purpose.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a