Hong Kong is 6 hours ahead of Brussels
Best overlap: 8:00 AM to 12:00 PM in Brussels is 2:00 PM to 6:00 PM in Hong Kong.
If you set up a recurring sync, 8:00 AM to 12:00 PM in Brussels (2:00 PM to 6:00 PM in Hong Kong) is the natural home for it. Hong Kong is 6 hours ahead of Brussels, which gives you a solid 4-hour window. Book earlier in it and neither side is rushing. Because Brussels and Hong Kong don't both observe daylight saving, plan to re-check the overlap around March and November.