Colombo is 10.5 hours ahead of Ottawa
There is no standard 8-to-6 overlap. Someone joins early or late.
Ottawa and Colombo are 10.5 hours apart, and that gap is wide enough that their normal 9-to-5 workdays never quite touch. If you meet regularly, fix one off-hours slot and rotate it between Ottawa and Colombo so the burden doesn't fall on one team. Keep an eye on the calendar — Ottawa observes daylight saving and Colombo doesn't, which nudges this window by an hour twice a year.