Cairo is 6 hours behind Shenzhen
Best overlap: 2:00 PM to 6:00 PM in Shenzhen is 8:00 AM to 12:00 PM in Cairo.
Schedule calls for 2:00 PM to 6:00 PM in Shenzhen — your colleagues in Cairo will be online from 8:00 AM to 12:00 PM. You share roughly 4 hours a day. That's enough for regular meetings, but treat the window as prime time and guard it. Remember that Cairo shifts for daylight saving and Shenzhen doesn't, so recalculate the overlap after each clock change.