Brasília is 5 hours behind Cairo
Best overlap: 1:00 PM to 6:00 PM in Cairo is 8:00 AM to 1:00 PM in Brasília.
Aim for 1:00 PM to 6:00 PM Cairo time — that's 8:00 AM to 1:00 PM over in Brasília. Brasília is 5 hours behind Cairo, which gives you a solid 5-hour window. Book earlier in it and neither side is rushing. Remember that Cairo shifts for daylight saving and Brasília doesn't, so recalculate the overlap after each clock change.