Beijing is 8 hours ahead of Reykjavik
Best overlap: 8:00 AM to 10:00 AM in Reykjavik is 4:00 PM to 6:00 PM in Beijing.
Your window to reach both cities is 8:00 AM to 10:00 AM in Reykjavik, which converts to 4:00 PM to 6:00 PM in Beijing. The shared window is only 2 hours — treat 8:00 AM in Reykjavik (4:00 PM in Beijing) as the one fixed point and plan everything else around it.