Abu Dhabi is 4 hours behind Shenzhen
Best overlap: 12:00 PM to 6:00 PM in Shenzhen is 8:00 AM to 2:00 PM in Abu Dhabi.
The overlap falls at 12:00 PM to 6:00 PM in Shenzhen, or 8:00 AM to 2:00 PM if you're in Abu Dhabi. The 4-hour gap barely gets in the way — you've got 6 hours of overlap, so pick whatever time fits the agenda.