Seoul is 15 hours ahead of Austin during US summer (CDT), and 14 hours ahead during winter (CST). When it's 9:00 AM in Austin, it's 11:00 PM or midnight in Seoul.
South Korea uses KST (UTC+9) year-round and doesn't observe DST.
Optimal window: 5:00 PM - 8:00 PM Austin time (8:00 AM - 11:00 AM Seoul next day). Evening calls from Austin catch morning business hours in Seoul.
Korean Air and connecting flights link Austin to Seoul Incheon International Airport.