Seoul is 8 hours ahead of Amsterdam during European summer (CEST), and 7 hours ahead during winter (CET). When it's 9:00 AM in Amsterdam, it's 4:00 PM or 5:00 PM in Seoul.
South Korea uses KST (UTC+9) year-round and doesn't observe DST.
Optimal window: 8:00 AM - 10:00 AM Amsterdam time (4:00 PM - 6:00 PM Seoul). Early morning calls from Amsterdam catch late afternoon business hours in Seoul.
KLM and Korean Air operate direct flights between Amsterdam and Seoul Incheon International Airport.