Prague is 1.5 hours behind Tehran
Best overlap: 9:30 AM to 6:30 PM in Tehran is 8:00 AM to 5:00 PM in Prague.
Your window to reach both cities is 9:30 AM to 6:30 PM in Tehran, which converts to 8:00 AM to 5:00 PM in Prague. 9 hours of shared hours is more than enough — slot meetings wherever they're most convenient for the people involved. One seasonal catch: Prague springs forward and falls back, but Tehran doesn't, so the gap changes by an hour for several months of the year.