Colombo is 4.5 hours ahead of Geneva
Best overlap: 8:30 AM to 1:30 PM in Geneva is 1:00 PM to 6:00 PM in Colombo.
Schedule calls for 8:30 AM to 1:30 PM in Geneva — your colleagues in Colombo will be online from 1:00 PM to 6:00 PM. Colombo is 4.5 hours ahead of Geneva, leaving about 5 hours of daily overlap — enough for most meetings if you don't leave them too late in the day. These times hold for most of the year, but Geneva's daylight saving (which Colombo doesn't use) shifts them by an hour twice annually.