Houston is typically 15 hours behind Seoul. When it's 11:00 PM in Seoul, it's 8:00 AM the same day in Houston. South Korea does not observe daylight saving time, but Houston does.
During US daylight saving time (March to November), the difference is 14 hours. During US standard time (November to March), the difference increases to 15 hours.
Optimal meeting window: 5:00 AM - 7:00 AM Houston time (7:00 PM - 9:00 PM Seoul, or 8:00 PM - 10:00 PM in winter). Very early morning Houston catches evening Seoul.
Houston's petrochemical industry has significant ties to South Korean companies, with several Korean conglomerates operating major facilities in the Houston area.