Quick answer
10 AM EST is midnight in Seoul (KST, UTC+9). During US daylight saving (EDT), 10 AM EDT is 11 PM in Seoul. South Korea is 14 hours ahead of EST and 13 hours ahead of EDT.
How to use this time conversion
The US-Korea time gap is one of the most challenging for live meetings. A 10 AM New York call reaches Seoul at midnight - outside any practical business hours. The best New York-to-Seoul slots are early morning US time (7-9 AM), which lands at early-to-late afternoon Seoul time.
What is 10 AM EST in Seoul?
10 AM EST is midnight KST in Seoul. During US daylight saving (EDT), 10 AM EDT is 11 PM in Seoul. Neither time is within Seoul business hours.
Why can the answer change?
The answer can change when one location observes daylight saving time and the other does not, or when they switch clocks on different dates.
What is a practical New York time to reach Seoul during business hours?
To reach Seoul at 9 AM-5 PM KST, you need 7 PM-3 AM EST or 8 PM-4 AM EDT in New York. The most common slot is 7-9 PM New York / 8-10 AM Seoul next day, or early morning New York catching late afternoon Seoul.
Can I compare this with more people?
Yes. Use the main Meeting Time Finder to add every participant and find the shared working-hours overlap.
Related timezone pages
new york seoul · san francisco seoul · 9am est in mumbai · 9am gmt in tokyo