Shanghai is 13 hours ahead of Ottawa
There is no standard 8-to-6 overlap. Someone joins early or late.
Ottawa and Shanghai are 13 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 Shanghai so the burden doesn't fall on one team. These times hold for most of the year, but Ottawa's daylight saving (which Shanghai doesn't use) shifts them by an hour twice annually.