Beijing is 7 hours ahead of Berlin (winter) or 6 hours ahead (summer). When it's 10:00 AM in Berlin, it's 5:00 PM in Beijing. China does not observe DST.
Berlin uses CET/CEST while Beijing uses CST (China Standard Time).
Optimal window: 8:00 AM - 11:00 AM Berlin time (3:00 PM - 6:00 PM Beijing). Early morning calls from Berlin reach late afternoon in Beijing.
Germany is China's largest European trading partner, making Berlin-Beijing communication frequent.