Fukuoka and Busan are in the same time zone. Both cities use UTC+9 (Japan Standard Time and Korea Standard Time). Neither observes daylight saving time.
When it's noon in Fukuoka, it's also noon in Busan.
Any time works! Since both cities are in the same time zone, scheduling is never an issue.
Fukuoka and Busan are sister cities just 200km apart across the Korea Strait. High-speed ferries connect the cities in about 3 hours, making them close economic partners.