Washington, D.C. is 7 hours behind Helsinki
Best overlap: 3:00 PM to 6:00 PM in Helsinki is 8:00 AM to 11:00 AM in Washington, D.C..
Keep meetings inside 3:00 PM to 6:00 PM in Helsinki — that maps to 8:00 AM to 11:00 AM in Washington, D.C.. Washington, D.C. is 7 hours behind Helsinki, leaving about 3 hours of daily overlap — enough for most meetings if you don't leave them too late in the day.