Stockholm is 6 hours ahead of Ottawa
Best overlap: 8:00 AM to 12:00 PM in Ottawa is 2:00 PM to 6:00 PM in Stockholm.
Both offices are open during 8:00 AM to 12:00 PM Ottawa time, which is 2:00 PM to 6:00 PM in Stockholm. You've got a decent 4-hour window. Set a recurring time near 8:00 AM in Ottawa (2:00 PM in Stockholm) and stick to it.