Wellington is 8.5 hours ahead of Tehran
Best overlap: 8:30 AM to 9:30 AM in Tehran is 5:00 PM to 6:00 PM in Wellington.
Book within 8:30 AM to 9:30 AM Tehran time (5:00 PM to 6:00 PM in Wellington) and both teams will be at work. The overlap barely stretches to 1 hour, so reserve it for what really needs a live conversation and handle the rest async. Don't be caught out by clock changes — Wellington observes daylight saving and Tehran doesn't, so the offset varies by an hour through the year.