Tehran is 1.5 hours ahead of Copenhagen
Best overlap: 8:00 AM to 5:00 PM in Copenhagen is 9:30 AM to 6:30 PM in Tehran.
Both teams are at their desks between 8:00 AM to 5:00 PM in Copenhagen and 9:30 AM to 6:30 PM in Tehran. Plenty of room to work with: 9 hours of daily overlap means you can prioritise people's preferences over the clock. Note the seasonal wrinkle: when Copenhagen is on daylight saving and Tehran isn't, the gap between them grows or shrinks by an hour.