Dhaka is 2 hours behind Shenzhen
Best overlap: 10:00 AM to 6:00 PM in Shenzhen is 8:00 AM to 4:00 PM in Dhaka.
Both teams are at their desks between 10:00 AM to 6:00 PM in Shenzhen and 8:00 AM to 4:00 PM in Dhaka. 8 hours of shared hours is more than enough — slot meetings wherever they're most convenient for the people involved.