Moscow is 1 hour ahead of Brussels
Best overlap: 8:00 AM to 5:00 PM in Brussels is 9:00 AM to 6:00 PM in Moscow.
Plan around 8:00 AM to 5:00 PM in Brussels, which is 9:00 AM to 6:00 PM in Moscow, to catch everyone during office hours. Moscow is 1 hour ahead of Brussels, but you'd hardly notice — 9 hours of shared hours makes this feel like working in neighbouring time zones. Seasonal note: Brussels uses daylight saving and Moscow doesn't, so double-check the times in your own months — they can move by an hour.