Seoul is 17 hours ahead of San Diego during standard time (or 16 hours during PDT). San Diego uses Pacific Time (PT, UTC-8/-7) while Seoul uses Korea Standard Time (KST, UTC+9). When it's 12:00 PM in San Diego, it's 5:00 AM the next day in Seoul.
South Korea does not observe daylight saving time, so the difference varies between 16 and 17 hours depending on whether San Diego is on PST or PDT.
Best calling time: 4:00 PM - 6:00 PM San Diego time. This corresponds to 9:00 AM - 11:00 AM the next day in Seoul, catching Korean morning business hours.
San Diego has a significant Korean-American community and business connections with South Korea. Korean electronics companies have partnerships with San Diego's tech sector. The US Navy presence in San Diego also maintains strong ties to South Korea.