Karachi is 1.5 hours ahead of Tehran
Best overlap: 8:30 AM to 4:30 PM in Tehran is 10:00 AM to 6:00 PM in Karachi.
Book within 8:30 AM to 4:30 PM Tehran time (10:00 AM to 6:00 PM in Karachi) and both teams will be at work. Karachi is 1.5 hours ahead of Tehran, but with 8 hours of common ground you can hold morning or afternoon meetings without anyone working odd hours.