Rio de Janeiro is 2 hours ahead of Ottawa
Best overlap: 8:00 AM to 4:00 PM in Ottawa is 10:00 AM to 6:00 PM in Rio de Janeiro.
Plan around 8:00 AM to 4:00 PM in Ottawa, which is 10:00 AM to 6:00 PM in Rio de Janeiro, to catch everyone during office hours. This is one of the easier pairings: 8 hours of shared time means flexible, low-stress scheduling. Note that Ottawa follows daylight saving while Rio de Janeiro stays put, so the times above drift by an hour seasonally.