Shenzhen is 13 hours ahead of Miami
There is no standard 8-to-6 overlap. Someone joins early or late.
Miami and Shenzhen have no natural overlap. The 13-hour gap is simply too large for regular working hours to meet. Treat the handoff like a relay — Miami wraps up and leaves notes for Shenzhen to pick up as their day begins. Bear in mind Miami shifts for daylight saving while Shenzhen stays fixed — recheck these hours after each clock change.