Cairo is 9 hours ahead of Mexico City
Best overlap: 8:00 AM to 9:00 AM in Mexico City is 5:00 PM to 6:00 PM in Cairo.
Book within 8:00 AM to 9:00 AM Mexico City time (5:00 PM to 6:00 PM in Cairo) and both teams will be at work. Cairo is 9 hours ahead of Mexico City, so common hours are scarce (about 1 hour). Lock the slot, keep it short, and follow up in writing. Daylight saving complicates things slightly: Cairo observes it, Mexico City doesn't, so the difference flexes by an hour part of the year.