Tehran is 1.5 hours ahead of Brussels

Best overlap: 8:00 AM to 5:00 PM in Brussels is 9:30 AM to 6:30 PM in Tehran.

For a call that suits both sides, look at 8:00 AM to 5:00 PM in Brussels / 9:30 AM to 6:30 PM in Tehran. Despite the 1.5-hour difference, a 9-hour overlap keeps things simple and gives both teams breathing room. Because Brussels and Tehran don't both observe daylight saving, plan to re-check the overlap around March and November.