Mexico City is 7 hours behind Geneva
Best overlap: 3:00 PM to 6:00 PM in Geneva is 8:00 AM to 11:00 AM in Mexico City.
Aim for 3:00 PM to 6:00 PM Geneva time — that's 8:00 AM to 11:00 AM over in Mexico City. With 3 hours of overlap, 3:00 PM in Geneva (8:00 AM in Mexico City) is a comfortable, repeatable slot for both sides. These times hold for most of the year, but Geneva's daylight saving (which Mexico City doesn't use) shifts them by an hour twice annually.